What happens to your respiratory system when you get older? An expert guide

It is a commonly cited statistic that after the age of 35, lung function begins a gradual and natural decline. This comprehensive guide explores what happens to your respiratory system when you get older, detailing the anatomical, physiological, and immunological changes that occur over time.

Quick Summary

As you age, your respiratory system experiences a natural decrease in lung tissue elasticity, weakening of breathing muscles like the diaphragm, and a less sensitive cough reflex, making you more susceptible to infections and other breathing issues.

Key Points

• Loss of Elasticity: Your lung tissue becomes less elastic, making it harder to exhale old air and reducing overall breathing efficiency.

• Weakened Muscles: The diaphragm and other breathing muscles weaken with age, decreasing the force of inhalation and exhalation, especially during exertion.

• Stiffening Chest Wall: Cartilage calcification and bone changes in the ribcage reduce chest wall flexibility, restricting lung expansion.

• Increased Infection Risk: A weaker immune system and a less effective cough reflex make older adults more vulnerable to respiratory infections like pneumonia.

• Proactive Management: Staying active, quitting smoking, and getting regular vaccinations are key strategies to minimize the effects of aging on your lungs.

• Reduced Gas Exchange: The surface area for gas exchange decreases, potentially leading to slightly lower oxygen levels in the blood, particularly during intense physical activity.

The Natural Progression of Respiratory Aging

As we journey through life, our body's systems undergo inevitable changes, and the respiratory system is no exception. While these changes are a normal part of aging, understanding them is the first step toward proactive health management. The lungs' structure and function, the mechanics of breathing, and the body's immune defenses all shift, sometimes subtly, but with cumulative effects that impact breathing efficiency and resilience against illness.

Anatomical and Mechanical Changes

The physical components of breathing, from the chest wall to the tiny air sacs in the lungs, change with age.

The chest wall and skeletal structure

• Stiffening of the ribcage: Over time, the bones of the ribcage become thinner and change shape. Cartilage connecting the ribs to the breastbone stiffens. This reduces the chest wall's flexibility and its ability to expand and contract efficiently during breathing.
• Weakening of breathing muscles: The diaphragm, the primary muscle for breathing, and the intercostal muscles between the ribs, gradually weaken. This reduces the force of both inhalation and exhalation, which can be particularly noticeable during physical exertion.
• Changes in spinal curvature: Conditions like osteoporosis can lead to changes in the shape of the spine, such as kyphosis, which can further restrict the ribcage's movement and compress the lungs.

Lung tissue and airways

• Loss of elasticity: The elastic fibers within lung tissue, which help the lungs recoil and push air out, lose their springiness. This can lead to smaller airways closing prematurely during exhalation, trapping old air in the lungs.
• Enlargement of airspaces: The tiny, grape-like air sacs called alveoli can lose their shape and become baggy or enlarged. This reduces the overall surface area available for gas exchange.

Changes in Gas Exchange and Lung Function

These anatomical and mechanical changes directly impact lung function, resulting in shifts in lung volumes and gas exchange efficiency.

• Decreased vital capacity: Vital capacity, the maximum amount of air that can be exhaled after a deep breath, decreases with age. This is due to the combination of reduced chest wall compliance and weaker respiratory muscles.
• Increased residual volume: Because airways close more easily and lung tissue is less elastic, more stale air gets trapped in the lungs. This increases the residual volume, the amount of air left in the lungs after a full exhale.
• Reduced gas exchange: The combination of a reduced alveolar surface area and potential ventilation-perfusion mismatching (where some air sacs receive air but not enough blood flow, or vice versa) leads to a less efficient transfer of oxygen into the bloodstream and carbon dioxide out of it. This can result in slightly lower blood oxygen levels, especially during exercise.

Immunological Shifts and Increased Vulnerability

Age-related changes also affect the body's defense mechanisms within the respiratory system.

• Weakened immune response: Immunosenescence, the gradual deterioration of the immune system, means older adults have a reduced ability to fight off respiratory infections like pneumonia, bronchitis, and the flu. The inflammatory response may also be altered, sometimes leading to more severe or atypical symptoms.
• Less sensitive cough reflex: The nerves in the airways that trigger a cough become less sensitive. A weaker cough is less effective at clearing irritants, mucus, and pathogens, allowing them to accumulate in the lungs and increasing the risk of infection.
• Impaired mucociliary clearance: The tiny, hair-like cilia lining the airways that sweep mucus and trapped particles out of the lungs become less effective with age, further hindering clearance.

Comparison: Young vs. Aged Respiratory System

Feature	Young Adult (approx. 25 years)	Aged Adult (approx. 70 years)
Lung Elasticity	High and resilient, with good recoil.	Decreased, leading to less effective exhalation.
Chest Wall Flexibility	High; able to expand and contract fully.	Reduced due to stiffening cartilage and bones.
Diaphragm Strength	Strong and efficient.	Weakened, reducing force of inhalation and exhalation.
Vital Capacity	At its peak.	Decreased.
Residual Volume	Low.	Increased.
Cough Reflex	Vigorous and highly sensitive.	Reduced sensitivity, less effective.
Immune Response	Robust and rapid.	Attenuated; higher risk of severe infection.

Managing Age-Related Respiratory Changes

While some aspects of respiratory aging are unavoidable, there are many things you can do to protect and support your lungs as you get older.

1. Stop smoking and avoid secondhand smoke: This is the single most important step for preserving lung health at any age. Smoking accelerates the aging process and causes irreparable damage.
2. Stay physically active: Regular aerobic exercise, even moderate intensity, strengthens the breathing muscles and improves overall cardiovascular function. This helps the body use oxygen more efficiently.
3. Maintain a healthy weight: Excess abdominal weight can restrict the diaphragm's movement and make breathing more difficult. A healthy diet supports both weight management and overall health.
4. Practice breathing exercises: Techniques like pursed-lip breathing can help keep airways open longer during exhalation and remove trapped air.
5. Stay up to date on vaccinations: Annual flu shots and the pneumococcal pneumonia vaccine are essential for protecting against infections that pose a higher risk to older adults.
6. Protect against air pollution: Both indoor and outdoor air pollutants can damage lungs. Monitor air quality alerts, ensure good ventilation in your home, and avoid areas with high traffic or industrial emissions.
7. Address underlying conditions: Effectively managing chronic conditions like heart disease, diabetes, or existing lung disease is crucial for overall respiratory health.

The Importance of Monitoring Your Lungs

Since age-related changes can mask or complicate symptoms of disease, monitoring your respiratory health is key. It's important to differentiate between typical age-related changes and signs of a potentially serious lung condition. Symptoms like persistent shortness of breath, a chronic cough, or wheezing should always be discussed with a doctor, as early detection can lead to better outcomes for conditions like COPD or pneumonia.

For more information on maintaining respiratory wellness throughout life, the American Lung Association provides valuable resources on their website: American Lung Association.

Conclusion

The aging respiratory system is a complex network of tissues, muscles, and defenses that, while naturally declining over time, is far from helpless. By understanding the normal changes that occur, and taking proactive steps to mitigate their impact, you can protect your lungs and maintain a high quality of life well into your senior years. The strategies for managing age-related changes—from regular exercise to staying current on vaccinations—are powerful tools for maximizing your respiratory health and resilience.

Frequently Asked Questions

Are breathing difficulties an inevitable part of getting older?

A gradual, subtle decline in respiratory function is a normal part of aging. However, significant breathing difficulties, chronic shortness of breath, or a persistent cough are not normal and should be evaluated by a healthcare professional. They could indicate an underlying condition exacerbated by age.

How does lung capacity change with age?

Lung capacity begins to gradually decline after the age of 35. Specifically, vital capacity (the maximum air you can exhale) decreases, while residual volume (the air remaining in your lungs) increases due to loss of lung elasticity and weaker muscles.

Why are older people more susceptible to pneumonia?

Older adults are more susceptible to pneumonia for several reasons, including a weaker immune system (immunosenescence), a less effective cough reflex for clearing pathogens, and potential comorbidities. This combination makes it harder to fight off infections.

Can exercise improve lung function in older adults?

Yes. While you cannot reverse the loss of lung elasticity, regular exercise can strengthen your respiratory muscles, improve cardiovascular function, and help your body use oxygen more efficiently, mitigating the effects of age-related decline.

What is 'senile emphysema'?

The term 'senile emphysema' refers to the age-related enlargement of lung airspaces due to the natural loss of elastic recoil. While functionally resembling emphysema, it is a normal physiological change and not a disease. It does, however, contribute to increased residual volume and less efficient breathing.

How can I tell the difference between normal aging and lung disease?

The key difference lies in the severity and persistence of symptoms. Normal aging changes are gradual and subtle. Symptoms like a persistent cough, chronic shortness of breath, wheezing, or chest pain are red flags and should be checked by a doctor to rule out conditions like COPD, asthma, or pneumonia.

Is it true that the cough reflex weakens with age?

Yes. Nerve sensitivity in the airways diminishes with age, making the cough reflex less robust. This can reduce the effectiveness of clearing mucus and foreign particles, increasing the risk of respiratory infections.