What Causes Shortness of Breath (Dyspnea)?

Shortness of breath (dyspnea) can be uncomfortable, even stressful, if you've ever thought, "I can breathe, but I feel like I can't." The feeling that you're not getting enough air can come on suddenly whether you are active or sedentary. It's normal for strenuous exercise, temperature changes, and obesity to make breathing difficult.

Shortness of breath may also indicate a health condition if your breathing suddenly changes for no reason you can identify. More severe causes include pneumonia, asthma, and heart problems. Read on to learn why you may feel like you can't breathe when you are.

Blocked or Narrow Airways

A blockage in the upper airway can narrow breathing passages, making it hard for air to travel naturally in and out of your body. This might cause shortness of breath as a result. The upper airway includes the larynx (voice box), pharynx (throat), and trachea (windpipe).

Irritated Lungs

Inflammation, which is an immune response to infection or injury, is a common cause of irritated lungs. Acute (short-term) inflammation is typically not dangerous. Chronic (long-term) inflammation may damage the airways and tissues in the lungs, making it harder to breathe.

Causes of inflammation may include:

• Asthma
• Autoimmune disorders
• Environmental irritants, such as air pollution or cigarette smoke
• Lung cancer
• Lung infections
• Trauma to the chest wall or lungs

Restricted Movement in the Lungs

Restrictive lung diseases are those that keep the lungs from expanding when you breathe in. These diseases reduce how much air you take in. Your breathing rate generally rises to send sufficient oxygen throughout your body. This may cause shortness of breath.

Is Shortness of Breath Hereditary?

Whether shortness of breath is hereditary is largely dependent on what's causing your symptoms. Some conditions are passed down between family members, while others, like infections, aren't. For example, alpha-1 antitrypsin (AAT) deficiency is an inherited gene disorder that might increase your risk of shortness of breath.

Shortness of breath is one of the first signs of AAT deficiency. Other symptoms can include fatigue, recurrent respiratory infections, and wheezing. Many people with AAT deficiency also develop emphysema, a lung disease that damages the alveoli, or tiny air sacs, in the lungs.

AAT deficiency runs in families. You're more likely to have the gene disorder if someone else in your family has it. You must have two mutated copies of the gene to have AAT deficiency. You're a carrier for the disease if you only have one mutated copy of the gene. However, your risk of certain lung diseases is higher than those with no mutated copies.

Who Gets Shortness of Breath?

The distribution of disease varies depending on the underlying cause. Shortness of breath commonly occurs in the following people:

• Age: Older adults are more likely to have shortness of breath than younger adults. Lung function generally decreases with age.
• Body mass index (BMI): People who have overweight or obesity more commonly experience shortness of breath than others. Excess adipose (fat) tissue may alter the immune response to airway inflammation and irritants, making these people likelier to have stronger respiratory symptoms than others.
• Sex: Females typically have narrower airways than males, increasing the risk of shortness of breath.

Risk Factors

Most shortness of breath is manageable with appropriate medication, breathing techniques, and exercise. However, if chest pain or pressure, fainting, or nausea accompanies it, treat it as a medical emergency.

If you're experiencing shortness of breath, a healthcare provider can help identify the cause and treat it. Here are some of the most common factors that increase the risk of shortness of breath.

Allergic Reactions

Severe allergic reactions (anaphylaxis) sometimes develop in response to specific allergens. Shortness of breath will quickly escalate if the reaction causes your throat to swell and close off, blocking your air supply.

Other symptoms of severe allergic reactions include:

• Diarrhea
• Itching
• Vomiting
• Wheezing

The remedy is getting a shot of epinephrine (adrenaline) immediately. People who have severe allergies carry EpiPens, which quickly deliver epinephrine by injection. Immediately head to an emergency room or call 911 if you don't have an EpiPen or don't know whether you have an allergy but suddenly have a severe allergic reaction.

Anemia

Iron is essential to the body. This mineral helps produce red blood cells, which carry oxygen from the lungs throughout the body. Iron also supports physical growth and brain development.

If you have anemia, your blood doesn't carry enough oxygen to the rest of your body. The most common cause of anemia is not having enough iron. Some evidence suggests that iron deficiency happens in about 4.5% to 18% of people in the United States.

You may feel short of breath more frequently when climbing stairs or completing your usual workout. You might eventually start getting breathless when resting. Anemia can also cause symptoms like dizziness, fatigue, and irritability.

Anxiety

One of the classic symptoms of an anxiety attack is feeling like you can't breathe. The feeling of hyperventilating, feeling like you can't catch your breath, is very common with an acute anxiety attack. Feeling short of breath can then make you more anxious, creating a vicious cycle and sometimes leading to outright panic.

Other anxiety symptoms include:

• Anxious thoughts or beliefs: These are hard to control, making you feel restless and tense and interfering with your daily life. They do not go away and can get worse over time.
• Changes in behavior: You may avoid everyday activities that you used to enjoy.
• Physical symptoms: This includes a pounding or rapid heartbeat, unexplained aches and pains, dizziness, and shortness of breath.

You can manage anxiety with relaxation and deep breathing techniques. Avoid the things that trigger you. You might consider limiting caffeine and alcohol and avoiding cigarettes, which can heighten anxiety.

Asthma

Shortness of breath is one of the hallmark symptoms of asthma, caused by narrow airways. Other asthma symptoms include:

• Chest tightness
• Coughing
• Wheezing

There are two main types of asthma: allergic and non-allergic. Each type has different causes and treatments. Allergic asthma is triggered by exposure to certain allergens, such as cigarette smoke, pollen, pet dander, dust mites, mold, and even weather elements. It's relatively easy to manage with medications.

Non-allergic asthma is harder to treat than allergic asthma and tends to affect people who are middle-aged or have overweight. It's not clear if losing weight helps alleviate non-allergic asthma.

Broken Ribs

Broken ribs can cause shortness of breath and piercing pain. They can also puncture your lung and lead to a collapsed lung (pneumothorax). Fractured ribs also raise the risk of pneumonia, especially among older adults.

There's no specific treatment for fractured ribs. A healthcare provider can care for a collapsed lung. Observation and oxygen therapy may be all that's needed if only a tiny portion of the lung has collapsed. A healthcare provider can insert a needle or tube into the chest, which can help if a significant portion of the lung is affected. Surgery may be necessary in some cases.

Carbon Monoxide Poisoning

Carbon monoxide is a severe hazard that can lurk very close to home. It's an odorless, tasteless, invisible gas produced by burning fuels in cars, trucks, fireplaces, furnaces, and grills. Carbon monoxide takes the place of oxygen in your red blood cells if you breathe it in—say, as it builds up in a small space with no ventilation, like a closed garage. This can lead to brain damage or even death.

Carbon monoxide poisoning symptoms can include:

• Confusion
• Dizziness
• Minor headache
• Shortness of breath

The best way to prevent carbon monoxide poisoning is to install a carbon monoxide detector in your home. These detectors look and act like smoke alarms, but they measure the concentration of carbon monoxide in the air. Also, check your heating system yearly, ensure good ventilation for all your appliances, and don't run your vehicle inside a closed garage.

Choking

Most people choking on a piece of food or anything else lodged in their throat know it immediately. It interrupts breathing and can kill you. Symptoms of choking include:

• Bluish skin color
• Inability to speak
• Loss of consciousness (unresponsiveness) if the blockage is not cleared
• Noisy breathing or high-pitched sounds while inhaling
• Shortness of breath
• Weak, ineffective coughing

Coughing is a good thing and should be encouraged if you're choking. It means your body is trying to expel the object. Talking is also good since it means air is passing across your vocal cords. It doesn't mean you're out of the woods, though. You still need to clear the blockage. 

The Heimlich maneuver is often effective. Someone stands behind the choking person and wraps their arms around the person's waist. They forcefully push into the choking person's abdomen, slightly above their belly button, until they spit out the object. You can even do the Heimlich maneuver on yourself by making a fist with one hand and then pushing it into your abdomen with the other hand.

Chronic Obstructive Pulmonary Disease (COPD)

Chronic obstructive pulmonary disease (COPD) involves constricted airways that cause shortness of breath. If you have COPD, you may be short of breath all the time, even sitting down. Shortness of breath more typically occurs every time you exercise. Other symptoms include wheezing, chest tightness, and a cough with mucus.

Smoking is the most common risk factor for COPD. Healthcare providers urge people with the condition who still smoke to quit. The condition has no cure, but treatments vary depending on its severity. These include medications, oxygen therapy, surgery, or, in severe cases, a lung transplant.

Heart Issues

Shortness of breath with or without chest discomfort can signify a heart attack. A heart attack is a medical emergency. Call 911 if you suddenly experience any of the warning signs.

Other heart attack symptoms include:

• Breaking out in a cold sweat, nausea, or lightheadedness
• Chest discomfort
• Pain in other areas of the upper body, such as one or both arms, the back, neck, jaw, or stomach

Low Blood Pressure

Low blood pressure (hypotension) can cause various symptoms, including shortness of breath. Other symptoms include:

• Blurry vision
• Confusion
• Dizziness or lightheadedness
• Fainting
• Feeling tired or weak
• Headache
• Heart palpitations, or feeling that your heart is skipping a beat, fluttering, or beating too hard or too fast
• Nausea
• Neck or back pain

Low blood pressure can be caused by dehydration, infection, pregnancy, certain medications, and conditions. Prevent low blood pressure episodes by staying hydrated, eating enough salt, avoiding alcohol, and wearing compression socks. A healthcare provider can rule out any conditions or medications that may cause your symptoms.

Lung Cancer

Different lung conditions, including lung cancer, can cause shortness of breath at different stages in their development. Other symptoms may include:

• Chest pain
• Coughing that progressively worsens or doesn't dissipate
• Coughing up blood
  
• Fatigue
• Weight loss without a known reason
• Wheezing
  

Lung cancer is often diagnosed in later stages when it's harder to treat. The disease generally doesn't cause symptoms in the early stages because it's localized. Lung cancer can block the airway when it grows larger.

Myasthenia Gravis (MG)

Myasthenia gravis (MG) causes chronic weakness of certain voluntary muscles, which are muscles you control. MG may affect your breathing muscles, resulting in shortness of breath.

Other MG symptoms generally depend on what muscles are affected but generally include:

• Blurry or double vision
• Changes in facial expressions
• Difficulty swallowing
• Eyelid drooping
• Speech problems
• Weak eye muscles
• Weakness in the arms, hands, fingers, legs, and neck

There's no cure for MG, but certain medications and lifestyle changes can strengthen your muscles. Anticholinesterase medicines, for example, improve nerve signals to your muscles. Lifestyle changes include getting plenty of rest, eating a nutrient-rich diet, and staying physically active.

Obesity

Pressure on the chest wall or pressure on the diaphragm from excess fat compresses the lungs. Inflammatory hormones secreted by excess body fat may also constrict the airways.

Having overweight or obesity can aggravate symptoms of asthma. Excess weight can make breathing hard for anyone, regardless of whether they have asthma.

Shortness of breath is a symptom of obesity hypoventilation syndrome (OHS). This condition causes inadequate breathing due to pressure on the chest. OHS lowers oxygen levels while raising carbon dioxide levels in the blood. If untreated, OHS can lead to heart problems and even death.

Pleurisy

Pleurisy is inflammation of the pleura, or the tissue that lines the chest and lungs. This inflammation may cause chest pain when you breathe or cough and shortness of breath. Other symptoms include coughing and rapid breathing.

Treatment typically depends on the cause. Antibiotics can treat bacterial infections, whereas viral infections go away on their own. You may require a tube to be inserted in the chest or surgery to drain fluid build-up in the space outside the lungs.

Pneumonia

Pneumonia is an infection in your lungs. There are several types, including viral and bacterial. Pneumonia generally causes your airways to swell and the air sacs in your lungs to fill with mucus, leading to shortness of breath and fatigue.

Other pneumonia symptoms include:

• Confusion, especially in older adults
• Cough, which may produce greenish, yellow, or even bloody mucus
• Fever, sweating, and shaking chills
• Loss of appetite, low energy, and fatigue
• Nausea and vomiting, especially in small children
• Rapid, shallow breathing
• Sharp or stabbing chest pain that gets worse when you breathe deeply or cough

Bacterial pneumonia can come on suddenly or over a few days and may also bring a high fever. Viral pneumonia usually appears over a few days and can feel much like the flu.

You can treat bacterial pneumonia with antibiotics. Antiviral medications may help with viral pneumonia. Vaccines against Streptococcus pneumoniae bacteria are recommended for young children, older adults, and people with certain conditions.

Pulmonary Embolism

A pulmonary embolism is a blood clot that has traveled from another body part (usually your legs) to your lungs. It causes sudden and severe shortness of breath, chest pain, and coughing up blood.

Some people are genetically predisposed to pulmonary embolisms. Others may be at risk because they smoke, are overweight, have been injured, or have other conditions like cancer. People who take certain medications, like birth control pills, may also have an increased risk.

Not moving for long periods can lead to a blood clot, which is why long plane trips can be dangerous for some people. You can help prevent pulmonary embolisms by regularly moving, especially on long trips. It's also important to drink plenty of fluids and wear compression socks if you're at risk.

The condition is potentially fatal and needs to be treated right away. Healthcare providers usually treat pulmonary embolisms with blood thinners or surgery.

Sarcoidosis

Sarcoidosis causes immune cells to form small, red lumps (granulomas) in the body that swell. These lumps commonly develop in the lungs and lymph nodes in the chest, but they can occur in any organ. You may have shortness of breath if sarcoidosis affects the lungs. Other symptoms can include coughing, chest pain, and wheezing.

There's no cure for sarcoidosis. A healthcare provider may prescribe medications that calm an overactive immune system and reduce inflammation. You may require oxygen therapy and surgery in some cases.

Smoking

Smokers' lungs become inflamed, inflaming the small airways and tissues. This can make the chest feel tight or cause wheezing or shortness of breath. After years of lung irritation, smokers may develop a chronic cough with mucus.

The longer you smoke, the worse your shortness of breath and other symptoms will become. Smoking also increases the risk of COPD, lung cancer, and other conditions. Don't start if you don't smoke. Talk to a healthcare provider about quitting if you already do. They can help you develop a plan to quit.

A Quick Review

Reasons why you may feel shortness of breath can be as harmless as exercise or as severe as lung cancer. Don't ignore any sudden changes in your breathing. Let a healthcare provider know if you are experiencing shortness of breath. They can perform diagnostic tests on your body and help you understand and resolve the symptoms.