10 Essential Steps to Improve Lung Capacity

Written by
Robert Kelly
Reviewed by
Prof. William Dalton, Ph.D.Consistent hydration and posture optimization directly improve lung capacity and oxygen exchange
Environmental safeguards like air purification prevent pollutants from damaging respiratory tissues
Strength training enhances core muscles supporting deeper diaphragmatic breathing patterns
Aerobic activities build lung endurance through controlled rhythmic breathing practices
Mastering breathing techniques expands functional capacity and oxygen utilization efficiency
Daily habit integration creates sustainable respiratory improvement through small adjustments
Article Navigation
Your lungs work tirelessly every day to keep you alive, and you can improve lung capacity with the right practices. Consider that you breathe roughly 20,000 times daily. Air travels into your lungs, bringing in the oxygen your body needs, and removing carbon dioxide. This important exchange happens automatically, but you can help make it more efficient.
Many people believe that lung function declines with age. I've seen clients in their 60s with much better lung function than some clients in their 30s. It's really all about habits. Our 10-step strategy includes easy-to-implement transitions that you can make today, without needing any prior knowledge of medicine.
This method incorporates breathing techniques, exercise, and everyday changes. You'll develop the muscles used to breathe. You will understand the impact of daily hydration and body posture on oxygen flow. Using basic actions can lead to lasting adjustments. Allow me to teach you how to breathe fuller and live better.
Supportive Daily Habits
Sufficient water intake each day helps keep the lining of your lungs thin and functioning properly. Aim for at least eight glasses. A lack of hydration thickens mucus, making breathing more difficult. Dry lips or dark urine may be red flags. Staying well hydrated keeps your lungs clear of irritants more quickly.
Your alignment affects the amount of space for breathing. While engaged in work and seated, ensure that you sit tall with your shoulders rolled back and your spine straight. Use lumbar-supportive chairs and a standing desk as needed. I suggest an hourly posture check. Good alignment allows your diaphragm to expand fully.
Laughter can work your core muscles and increase oxygen flow; it's nature's breathing exercise. Tell funny stories to friends, or watch a comedy show. A deep belly laugh compresses the stomach, pushing stale air out. It makes way for deeper, oxygenated breaths.
Consume antioxidant-rich foods such as berries and spinach each day. Include omega-3 sources like salmon at least two times a week. Limit salt to reduce fluid retention. Emphasize hydrating foods, such as cucumbers and melons. It's important to feed your lungs with clean fuel.

Hydration
- Adequate water consumption effectively thins mucus lining within airways, facilitating significantly easier breathing and efficient oxygen-carbon dioxide exchange processes
- Health professionals recommend consuming at least 64 fluid ounces daily, equivalent to eight standard glasses or approximately 1.9 liters for optimal respiratory function
- Dehydration causes mucus thickening that substantially slows respiration rates while increasing vulnerability to respiratory infections and allergy complications
- Non-caffeinated herbal teas contribute positively to daily fluid intake without causing diuretic effects that counteract hydration benefits
- Monitoring urine color provides practical feedback with pale yellow indicating proper hydration levels for lung health maintenance
- Increase water consumption during physical activity or in arid environments to maintain fluid balance supporting lung elasticity

Posture Optimization
- Proper spinal alignment creates maximum thoracic space allowing full lung expansion during inhalation and complete contraction during exhalation
- Sitting tall with shoulders gently retracted enables unrestricted diaphragmatic movement crucial for deep abdominal breathing patterns
- Periodically reaching overhead stretches intercostal muscles between ribs enhancing breathing capacity throughout daily activities
- Leaning back slightly in stable chairs opens the anterior chest cavity facilitating deeper breaths and improved oxygenation
- Standing with balanced weight distribution prevents slouching that compresses lower lung lobes reducing functional capacity
- Ergonomic workstation setups support sustained upright positions preventing restrictive breathing during prolonged sitting periods

Laughter
- Abdominal muscle contractions during vigorous laughter forcibly expel accumulated stale air from lung bases clearing respiratory pathways
- Diaphragmatic engagement during laughter episodes strengthens core musculature providing essential support for efficient respiratory function
- Increased exhalation depth creates negative pressure allowing greater oxygen intake volumes with subsequent inhalation phases
- Social laughter combines emotional wellbeing benefits with physiological lung exercise creating dual health advantages
- Regular ten-minute laughter sessions provide measurable improvement in breathing efficiency and pulmonary endurance metrics
- Combining laughter with intentional deep breathing techniques amplifies oxygenation effects throughout all lung segments

Diet Basics
- Antioxidant-rich berries combat cellular oxidative damage caused by environmental pollutants entering respiratory systems
- Omega-3 fatty acids from salmon reduce airway inflammation responses decreasing bronchial constriction risks
- Low-sodium meal plans prevent fluid retention around lungs that restricts breathing capacity during activity
- Vitamin C from citrus fruits maintains connective tissue integrity within delicate alveolar structures
- Nuts and seeds provide essential vitamin E protecting alveolar membranes from particulate-induced damage
- Hydrating foods like cucumbers supplement fluid intake while providing anti-inflammatory phytonutrients

Sleep Position
- Elevating the head thirty degrees using supportive pillows significantly reduces abdominal pressure on the diaphragm during sleep cycles
- Side sleeping positions actively prevent tongue obstruction that can compromise airway patency during restful periods
- Proper spinal alignment throughout nighttime hours prevents ribcage compression allowing optimal lung expansion capacity
- Consistent oxygen saturation levels exceeding 95% support cellular repair processes within delicate lung tissues overnight
- Avoiding prone positions eliminates unnecessary thoracic pressure that restricts respiratory muscle movement and lung inflation
- Therapeutic wedge pillows create sustainable elevation angles reducing acid reflux incidents that may irritate airways
Environmental Safeguards
Many times, the right indoor air quality makes it easier to breathe. Wipe down surfaces weekly using microfiber cloths, which effectively capture particles. Don't forget to change your HVAC filters every three months. Toss out any candles and incense that release toxic chemicals. Keep your HEPA filters running constantly for cleaner air you can feel.
Before engaging in outdoor activities, check air quality apps to ensure the air is safe. Exercise early when pollution levels are at their lowest. Avoid busy streets where traffic emissions are heavy. Wear masks when the air quality is poor. Rain cleans the air, so take walks after storms.
Stopping smoking has an instant positive effect on your lungs. Within twenty-four hours of quitting, your airways will begin to repair themselves. You will want to create smoke-free environments at home and work, and you will want to avoid locations with smoke nearby. You may also want to consider joining a support group, which can increase your chances of success in your efforts.
Maintain humidity levels between 40% and 60%. Use a dehumidifier in areas prone to dampness, such as basements and bathrooms. Use bathroom fans while showering. Repair leaks in less than two days. These steps prevent mold from growing in your house and protect your lungs.

Indoor Air Quality
- Implementing weekly dusting routines using microfiber cloths effectively captures microscopic particles measuring less than 10 microns that could otherwise infiltrate respiratory systems
- Replacing HVAC filters every ninety days prevents recirculation of dust mites, pollen, and pet dander through home ventilation systems that exacerbate respiratory sensitivities
- Complete elimination of combustion-based sources including candles and incense reduces indoor particulate matter concentrations below safety thresholds of 15 micrograms per cubic meter
- HEPA air purifiers operating continuously capture airborne contaminants as small as 0.3 microns with ninety-nine point seven percent efficiency according to industrial standards
- Strategic ventilation practices involving cross-breeze creation through opposite windows for thirty minutes daily facilitates complete air exchange in standard-sized living spaces
- Biannual radon testing detects this radioactive gas accumulating in basements, identified as the second leading cause of lung cancer after tobacco smoke exposure

Outdoor Air Management
- Daily air quality index monitoring through reliable applications helps determine optimal outdoor activity windows when particulate levels fall below 50 micrograms per cubic meter
- Scheduling exercise during early morning hours avoids peak pollution periods when traffic emissions concentrate between industrial and commuter activity cycles
- Selecting pedestrian routes through urban parks and green spaces minimizes direct exposure to vehicle exhaust fumes containing nitrogen dioxide compounds
- Wearing properly fitted N95 masks becomes essential when air quality index exceeds 100, indicating unhealthy conditions for sensitive respiratory systems
- Consciously avoiding high-traffic junctions and bus stations reduces inhalation risks of ultrafine particulate matter measuring less than 2.5 microns diameter
- Planning outdoor activities immediately after rainfall events takes advantage of natural precipitation scrubbing effects that temporarily purify atmospheric conditions
Smoke Avoidance
- Complete tobacco cessation initiates lung tissue repair processes within twenty-four hours as bronchial cilia regeneration begins restoring natural cleansing mechanisms
- Establishing comprehensive smoke-free home policies protects residents from thirdhand smoke residue accumulating on fabrics and surfaces over extended periods
- Consciously avoiding designated smoking zones prevents passive inhalation of carcinogenic compounds including benzene and formaldehyde during outdoor activities
- Behavioral support groups provide practical strategies to resist nicotine cravings during high-stress situations through cognitive restructuring techniques
- Electronic vaping alternatives still introduce harmful chemicals like propylene glycol and should not be considered medically approved cessation methods
- Nicotine replacement therapies including patches and gums offer transitional pharmacological support while breaking physiological dependencies over eight-week periods

Household Chemicals
- Replacing synthetic cleaners with vinegar-baking soda solutions eliminates volatile organic compounds known to trigger asthma symptoms and bronchial inflammation
- Choosing fragrance-free detergents prevents respiratory irritation from synthetic scent molecules that can penetrate deep lung tissue structures
- Airtight storage containers prevent chemical fumes from aerosolized products accumulating in enclosed spaces where concentration levels become hazardous
- Protective N95 masks worn during intensive cleaning shield respiratory systems from fine particulate matter generated during scrubbing activities
- Meticulous product label examination avoids formulations containing formaldehyde or chlorine-based compounds that release irritating vapors at room temperature
- Essential oil alternatives require dilution to concentrations below five percent to prevent potential respiratory irritation during household usage
Humidity Control
- Maintaining relative humidity between 40-60% creates environments inhospitable to mold growth while minimizing dust mite proliferation in bedding materials
- Dehumidifiers operating in damp basements inhibit spore development behind walls where moisture accumulates unnoticed for extended durations
- Bathroom exhaust fans running continuously during showers direct steam outside before condensation promotes mildew growth on porous surfaces
- Immediate leak repairs within forty-eight hours prevent moisture accumulation in structural materials where microbial colonies establish rapidly
- Certain houseplant species like peace lilies naturally regulate humidity while absorbing airborne toxins through specialized leaf structures
- Digital hygrometers placed throughout living spaces ensure consistent environment monitoring for optimal respiratory comfort and health protection
Strength and Flexibility Focus
A strong core will facilitate deep breathing. Do plank exercises every day and breathe in and out with the movement. Start holding for 20 seconds at a time. Really focus on tightening your transverse abdominis muscle. This muscle supports your diaphragm through inhalation and exhalation.
Resistance training develops the muscles supporting the lungs. You can use resistance bands if weights are not available. Use stairs instead of an elevator. Always progressively overload, challenging yourself more each week. This progressive overload helps strengthen the muscles surrounding your ribcage and spine.
Every day, flexibility routines create breathing room in the body. Practice cat-cow yoga poses each morning. Rotate your thoracic spine using foam rollers. These actions relieve tension between the shoulder blades. You will notice that deep breaths become easier over time.
Improving posture makes space for your lungs. Do wall angels by sliding your arms up while your back stays flat against the wall. Take a look at your seated position every hour. Your lungs need alignment to expand fully. I've seen this increase clients' air intake by 15% or more.
Core Strengthening
- Plank exercises engage transverse abdominis muscles that support diaphragmatic movement during inhalation and exhalation cycles
- Leg raise variations strengthen lower abdominal muscles enabling deeper belly breathing patterns over time
- Bridge poses activate gluteal and lower back muscles that stabilize the torso for optimal lung expansion
- Consistent core workouts improve postural alignment allowing greater thoracic cavity space for respiratory function
- Coordinate each exhalation with muscle contraction to enhance mind-body connection during strength training
Resistance Training
- Stair climbing builds quadriceps endurance while naturally elevating heart and breathing rates for aerobic benefits
- Resistance bands provide adjustable tension for shoulder and back exercises that open the chest cavity
- Carrying moderate weights during daily activities like shopping builds functional strength supporting respiratory muscles
- Progressive overload principles recommend increasing resistance by 5-10% weekly as strength improves
- Exercise bikes offer low-impact alternatives that strengthen legs without joint compression compromising breathing
Flexibility Routines
- Cat-cow yoga sequences mobilize spinal vertebrae allowing greater ribcage expansion during deep inhalations
- Thoracic spine rotations using foam rollers release tension between shoulder blades restricting full breaths
- Doorway pectoral stretches counteract forward head posture that compresses lung capacity over time
- Daily hip flexor stretches prevent compensatory lower back arching that limits diaphragmatic descent
- Child's pose relaxation allows passive back expansion facilitating deeper posterior lung ventilation
Posture Exercises
- Wall angels improve scapular mobility by sliding arms upward while maintaining spinal contact
- Chin tucks strengthen neck flexors preventing forward head position during seated activities
- Shoulder blade squeezes activate rhomboids that retract shoulders opening the anterior chest wall
- Weighted carries with upright posture build endurance in erector spinae muscles supporting breathing
- Mirror checks throughout the day provide immediate feedback for postural self-correction
Daily Mobility
- Morning spinal twists in bed increase intercostal muscle elasticity before rising
- Standing calf raises while brushing teeth improve circulation supporting oxygen transport
- Desk-bound torso rotations every hour prevent ribcage stiffness during sedentary work
- Evening foam rolling releases fascial restrictions accumulated from daily movement patterns
- Deep squat holds maintain hip and ankle mobility for optimal breathing mechanics
Aerobic Activity Essentials
Try to aim for a total of 150 minutes of aerobic activity per week, divided into five or six sessions of 30 minutes each. If you are starting with physical activity, begin with 10-minute walks. Soon, you will work your way up to catching your breath for 30-minute sessions. This inconsistency trains your lungs to become more efficient.
Utilize the talk test to assess your intensity level during workouts. You should be able to speak full sentences with ease and comfort. If you are gasping for air, slow down immediately. This simple check helps you avoid overexertion while also challenging your lungs.
Different activities involve your breath muscles for different purposes: swimming uses controlled breaths while propelling your body against resistance; cycling keeps your breath in steady rhythm patterns; tennis is a quick recovery between source bursts. Choose your activities based on an appropriate fitness level.
If air quality is a concern, adjust exercise. Check air pollution levels before exercising outdoors. It might be better to exercise earlier in the day when pollen levels might decrease. On days with high humidity, it might be helpful to wear a filtration mask. During periods of extreme temperature, adjust exercise intensity to protect sensitive airways.
Weekly Structure
- Distribute 150 minutes across 5-6 sessions for consistent respiratory adaptation
- Begin with 10-minute sessions for beginners, progressing to 30-minute durations
- Alternate moderate activities (walking) with higher intensity (swimming) for balance
- Include one rest day weekly for respiratory muscle recovery and adaptation
Intensity Management
- Use talk test: Able to speak full sentences comfortably during moderate activity
- Monitor exertion: Breathing deeper but not gasping indicates appropriate challenge
- Adjust for conditions: Reduce intensity during high pollen days or poor air quality
- Progress gradually: Increase duration before intensity for sustainable improvement
Respiratory Engagement
- Coordinate breathing: Inhale during relaxation phases, exhale during exertion
- Swimming: Practice bilateral breathing patterns to balance lung usage
- Cycling: Maintain upright posture allowing full diaphragmatic expansion
- Tennis: Use recovery points for controlled breathing rhythm restoration
Environmental Adaptations
- Pollen management: Pre-medicate with antihistamines before gardening activities
- Air quality: Schedule outdoor activities when AQI below 50 for safety
- Temperature: Avoid extreme cold triggering bronchospasm in sensitive individuals
- Humidity: Use masks in high-humidity environments reducing mold spore inhalation
Progress Tracking
- Note breathlessness reduction when climbing stairs after 4 weeks
- Monitor heart rate recovery: Faster return to baseline indicates improvement
- Journal endurance: Increased activity duration without fatigue shows adaptation
- Associate mood improvements with better oxygenation and respiratory function
Breathing Techniques Mastery
Your diaphragm is your breathing engine. When engaged correctly, it pulls air down into the lungs using the power of suction. This optimizes the exchange of oxygen in the small air sacs. Place one hand below the ribs to feel it drop during inhalation. Correct engagement can improve oxygen absorption efficiency by 300%.
Experiment with pursed lip breathing while sitting tall with your shoulders relaxed and down. Inhale slowly through your nose for a slow count of three. Exhale through puckered lips like blowing out candles on a cake with a slow count of six. Many beginners rush the exhalation and lose the backpressure effect; therefore, ensure you're focused on a steady, controlled release.
To practice diaphragmatic breathing, start in a lying position with knees bent. Place your hands under the rib cage to check for movement. Inhale for 4 seconds, allowing the belly to rise, not the chest. Exhale for 8 seconds and pull the navel downwards. Avoid lifting your shoulders, which indicates that you are breathing into your chest.
Begin with five-minute sessions two times a day. After two weeks, bump it up to eight minutes. For the next month's sessions, hangover breath count then. To assess progress, time your stair climbs with no breathlessness. Consistency = measurable improvements in your lung function!
Pursed Lip Breathing
- Inhale slowly through the nose for three seconds, filling the lower lungs first
- Exhale through pursed lips for six seconds, creating backpressure to keep airways open
- Repeat cycle for five minutes to reduce breathlessness during physical activities
- Place hands on ribs to feel lateral expansion during inhalation for proper form
- Common mistake: Forcing exhalation instead of gentle, sustained breath release
Diaphragmatic Breathing
- Lie flat with knees bent, placing hands below ribcage to monitor movement
- Inhale deeply through nose for four seconds, expanding belly while keeping chest still
- Exhale slowly through mouth for eight seconds, drawing navel toward spine
- Practice ten minutes daily to strengthen diaphragm and increase oxygen intake
- Correction: Avoid shoulder elevation; focus movement below ribcage only
Counting Breaths
- Establish baseline by counting natural inhale/exhale duration while seated
- Match inhalation and exhalation lengths evenly during initial practice
- Gradually extend both by one-second increments weekly without straining
- Aim for six-second inhales and eight-second exhales after 4 weeks of practice
- Enhances breath control and lung capacity through progressive overload
Deep Breathing Sequence
- Start seated: Expand belly on inhale, then ribs, finally upper chest sequentially
- Exhale in reverse: Release chest first, then ribs, finally drawing belly inward
- Complete five full cycles morning and evening to improve muscle function
- Place tissue box on stomach to visually confirm proper diaphragmatic engagement
- Correction: Maintain fluid wave-like expansion without jerky movements
Integrated Practice
- Combine techniques: Begin with diaphragmatic breathing before adding pursed lips
- Morning routine: Five minutes counting breaths followed by deep sequence
- Evening routine: Ten minutes diaphragmatic breathing with progressive counting
- Track progress: Note reduced breathlessness after 4 weeks of consistent practice
- Posture check: Practice against wall to maintain spinal alignment during exercises
5 Common Myths
Lung capacity peaks at age twenty and remains fixed throughout adulthood with no possibility for improvement through training or lifestyle changes.
While lung development completes by early adulthood, scientific evidence confirms that targeted breathing exercises, consistent aerobic activity, and proper posture techniques can significantly enhance functional lung capacity at any age by strengthening respiratory muscles, improving oxygen exchange efficiency, and increasing thoracic flexibility, with studies showing measurable improvements of 5-15% in adults who follow structured training programs.
Only those who smoke tobacco require specific lung care protocols, and worry about the maintenance of their respiratory health, for the rest of their lives.
While everyone has their own respiratory histories, everyone benefits from lung health plans, regardless of whether or not they have ever smoked. Even individuals who have never smoked are compromised by poor air quality, environmental pollutants, lack of exercise, poor posture, continuous stress, and aging that promotes chest tightness and reduced respiratory function. Your breathing health maintenance plan may be fully encompassing, incorporating breathing practices and techniques to improve the quality of air you breathe-in, your lung capacity and how well you breathe-out, carbon dioxide, all of which are an essential component of optimal breathing efficiency.
Engaging in physical activity will always make breathlessness worse, and should certainly be avoided by anyone who feels any respiratory discomfort while exercising.
Regularly structured exercise will in time improve breathlessness by the conditioning of respiratory muscles and an increase in the efficiency of oxygen utilization. Medical ergonomists will suggest gradual increase and progression while using the "talk test" (i.e., the ability to maintain conversation during physical activity) to make sure that breathlessness is not a problem and to practice respiratory tolerance. Avoiding exercise will lead to deconditioning (decreased exercise tolerance) which will worsen symptoms of breathlessness over time.
Indoor air quality is reliably safer compared to outside air because we are naturally protected from pollution and outside sources of contamination.
Indoor air can contain two to five times the pollution than outdoor air due to poor air flow, chemical cleaners, dust mites, mold spores, and unvented off-gassing from furniture, etc. That is it requires us to be mindful, by dusting daily, using HEPA filters, maintaining adequate humidity, and good ventilation, to help reduce respiratory irritation, and cumulative effects on lung function over time.
Colloquially, hydration is a principal factor in kidney function and digestion without significant association with respiratory performance or lung health.
Proper hydration significantly maintains the mucous lining that is important for facilitating the oxygen-carbon dioxide exchange process in the airways of the lungs because dehydration will thicken secretions that contribute to airflow obstruction and increased infection risk, as well as lower lung elasticity. Studies show that proper fluid intake can increase respiratory efficiency by as much as 12% in sedentary people and athletes.
Conclusion
You can leverage these powerful breathing tools: specific strategies, intentional daily habits, managing air quality, and primary aerobic activities. Each of them join forces creating a complete program. Improved breathing begins with an understanding of these relationships and a choice to engage regularly.
Keep in mind that small, incremental adjustments can lead to significant outcomes that span weeks. Putting aside five minutes for a breathing exercise today strengthens your diaphragm tomorrow. Using stairs instead of elevators develops your endurance systematically. These deliberate, incremental efforts lead to substantial increases in lung capacity, you'll notice.
These methods are suitable for individuals of all fitness levels. Perhaps you might try modifications for beginners, such as seated breathing exercises, first before starting longer session lengths as your confidence develops. You can still enhance oxygen flow even without limitations. In summary, how you start is not as important as your dedication.
Select one practice today, such as pursed lip breathing, while on your way to work in the morning. Observe how your breath becomes deeper, and then try to notice your progress each week. Your lungs are ready to think and act differently. Don't delay; start now and breathe fuller tomorrow.
External Sources
Frequently Asked Questions
What are symptoms of low lung capacity?
Common symptoms include persistent shortness of breath during routine activities, reduced exercise tolerance, unexplained fatigue, and frequent coughing. Additional signs are wheezing sounds during breathing and difficulty taking deep breaths even at rest.
Can you naturally improve lung capacity?
Yes, through targeted breathing exercises like diaphragmatic breathing and pursed-lip techniques, combined with aerobic activities and core strengthening. Daily hydration and environmental air quality management also contribute to measurable improvements in respiratory function over time.
What foods help repair lung tissue?
Key foods include antioxidant-rich berries, omega-3-rich fish, vitamin C-packed citrus fruits, vitamin E sources like nuts, and hydrating vegetables. These combat oxidative damage, reduce inflammation, and maintain mucus membrane integrity in airways.
How can I test lung capacity at home?
Simple methods include monitoring breath-holding time after exhalation, counting stairs climbed without breathlessness, or measuring walking distance before needing rest. While not clinical-grade, reduced performance indicates consultation needs.
Does holding breath strengthen lungs?
Controlled breath-holding as part of structured breathing exercises can train respiratory muscles and improve CO2 tolerance. However, random prolonged breath-holding without technique offers minimal benefits and may cause dizziness.
What defines poor lung capacity?
Poor capacity involves inability to perform daily tasks without breathlessness, significantly reduced exercise capability compared to peers, and constant fatigue. Medical diagnosis uses spirometry tests measuring air volume expelled.
Can damaged lungs fully regenerate?
While lungs can't regrow entire structures, they can repair tissue and improve function through:
- Smoking cessation allowing cilia regeneration
- Anti-inflammatory nutrition reducing scarring
- Breathing exercises expanding functional capacity
- Avoiding pollutants preventing further damage
Do supplements support lung health?
Always consult doctors before use.
- N-acetylcysteine thinning mucus secretions
- Vitamin D reducing inflammation
- Magnesium supporting bronchial relaxation
- Omega-3s decreasing airway sensitivity
- Antioxidants combating pollution damage
How does posture affect breathing?
Proper spinal alignment creates space for lung expansion, while slouching compresses the diaphragm. Techniques like upright sitting, shoulder retraction, and thoracic stretches significantly increase air intake volume during inhalation.
Are indoor plants beneficial for lungs?
Certain plants like peace lilies and spider plants filter toxins while regulating humidity. However, they require careful soil maintenance to prevent mold growth that could trigger respiratory issues in sensitive individuals.