15 Reasons You're Short of Breath

Shortness of breath can be caused by something as innocent as exercise to more serious issues like pneumonia, asthma, and even heart failure or lung cancer.

Acute shortness of breath comes on very suddenly, while chronic shortness of breath means the symptom builds more slowly and can last a long time. Acute and chronic shortness of breath are very different entities.

“If you develop sudden and severe shortness of breath, head to the emergency room,” says Norman Edelman, MD, senior scientific officer of the American Lung Association. “If you have more progressive shortness of breath that gets worse over weeks and months, certainly see your doctor.”

Definitely get medical help if you have shortness of breath plus other respiratory symptoms like chest pain or coughing up blood.

Learn the more common reasons for shortness of breath below so you can get help.

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Shortness of breath is one of the hallmark symptoms of asthma, along with wheezing, coughing, and chest tightness. These are caused by airways which have narrowed, making it harder for air to travel naturally in and out of your body. There are two main types of asthma: allergic and non-allergic, each with very 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. This type of asthma is relatively easy to manage with medications.

Non-allergic asthma is more mysterious and harder to treat and tends to strike middle-aged, overweight women, Dr. Edelman explains. It’s not clear if losing weight helps alleviate non-allergic asthma.

Many people don’t realize you can develop asthma not only in childhood but also as an adult. In both cases, it tends to be chronic.

COPD stands for chronic obstructive pulmonary disease. The two main types are chronic bronchitis and emphysema. Like asthma, COPD involves constricted airways that cause not just shortness of breath but also wheezing, chest tightness, and a cough with mucus.

“If you have COPD, you may be short of breath all the time, even sitting down,” says Dr. Edelman. “It more typically occurs every time you exercise.” COPD is more common in older individuals and tends to get worse over time.   

Smoking is the number one risk factor for COPD, and people with COPD who still smoke are urged to quit.   

There’s no cure for the condition, but there are treatments that vary depending on how severe it is. These span the spectrum from medications, oxygen therapy, surgery, or, in extreme cases, a lung transplant.

RELATED: 15 Symptoms of COPD

A pulmonary embolism is a clot that has traveled from another part of your body (usually your legs) to your lungs. It causes sudden and severe shortness of breath, along with chest pain and sometimes coughing with blood. The condition is potentially fatal and needs to be treated right away.

Some people are genetically predisposed to pulmonary embolisms or may be at risk because they smoke, are overweight, have been injured, have other conditions like cancer, or are taking certain medications, including birth control pills. Not moving for long periods of time also raises your risk, which is why long plane trips can be dangerous for some people.

You can help prevent pulmonary embolisms by making sure you move regularly, especially on long trips, drinking plenty of fluids, and wearing compression socks. This type of clot is usually treated with blood thinners or surgery.

Carbon monoxide is a serious hazard that can lurk very close to home. It’s an odorless, tasteless, invisible gas that’s produced by burning fuels in cars, trucks, fireplaces, furnaces, and grills. If you breathe it in–say, as it builds up in a small space with no ventilation, like a closed garage–it takes the place of oxygen in your red blood cells, which can lead to brain damage or even death. Carbon monoxide poisoning symptoms can include shortness of breath, confusion, dizziness, and a minor headache, and it can be both acute and chronic.

“Acute would be a smoke-inhalation-fire scenario,” says Sean Drake, MD, a general internist with Henry Ford Health System in Sterling Heights, Michigan. “You also see [carbon monoxide building up] in homes. That can be more chronic, insidious.”

The best way to prevent carbon monoxide poisoning is to install a carbon monoxide detector in your home. They look and act a lot like the smoke alarms you should also have installed, but they measure the concentration of carbon monoxide in the air. Get your heating system checked every year, make sure you have good ventilation for all your appliances, and don’t run your vehicle inside a closed garage.

Severe allergic reactions–called anaphylaxis, anaphylactic shock, or allergic shock–sometimes develop in response to certain allergens. Bee stings and peanuts are good examples.

Shortness of breath will quickly escalate if the reaction causes your throat to swell and close off, blocking your air supply. You may also itch, wheeze, and have vomiting and diarrhea.

The remedy is to get a shot of epinephrine (adrenaline) right away. People who know they have severe allergies usually carry EpiPens with them. If you don’t have an EpiPen, or don’t know you have an allergy but suddenly have any of these symptoms, head to an emergency room or call 911.

Most people who are choking on a piece of food or anything else lodged in their throat usually know it right away. It interrupts breathing immediately–and can kill you.

Coughing is a good thing and should be encouraged. It means your body is trying to expel the object. Talking is also good. “That means air is passing across your vocal cords,” says Dr. Drake.

It doesn’t mean you’re out of the woods, though. You still need to get rid of the problem. The Heimlich maneuver is often effective. It involves standing behind the person who is choking, wrapping your arms around their waist, and forcefully pushing into their abdomen slightly above their bellybutton until they spit out the object. You can even do the Heimlich maneuver on yourself, by making a fist with one hand then pushing it into your abdomen with the other hand.

RELATED: 7 Kinds of Coughs and What They Might Mean

Pneumonia is an infection in your lungs. There are two types: viral and bacterial. Shortness of breath is common with viral pneumonia, sometimes also called walking pneumonia, says Dr. Edelman. This type is also less severe than bacterial pneumonia and usually clears up in one to three weeks.

Pneumonia in general causes your airways to swell and the air sacs in your lungs to fill with mucus, leading to shortness of breath and fatigue. Bacterial pneumonia can come on suddenly or over a few days and may also bring on a high fever. Viral pneumonia usually appears over a few days and can feel a lot like the flu.

Bacterial pneumonia can be treated with antibiotics. Antiviral medications may help viral pneumonia. There are also vaccines against Streptococcus pneumoniae bacteria, which is the most common cause of bacterial pneumonia, that are recommended for young children, older adults, and people with certain health conditions.

Way less common than high blood pressure, low blood pressure can nevertheless cause health problems, and shortness of breath is one. Extremely low blood pressure–called hypotension–can also cause dizziness and even make you faint.

Low blood pressure (usually a reading of 90/60 or lower), can be caused by dehydration (even from exercising strenuously), infection, pregnancy, and certain medications and medical conditions.

There are also specific types of low blood pressure. Orthostatic hypotension, for instance, is when your blood pressure drops suddenly when you stand up from sitting or lying down. Postprandial hypotension happens after you eat. Abnormalities in your brain or nervous system can also cause blood pressure to drop.

Stave off low blood pressure episodes by staying hydrated, eating enough salt, avoiding alcohol, wearing compression socks, and ruling out any medical conditions or medications that may be contributing to your symptoms.

RELATED: 13 Reasons You’re Dizzy–and What to Do About It

Your heart and your lungs are closely linked. Anything that decreases the heart’s ability to pump blood will also make you short of breath, says Dr. Edelman.

“The general rule is that if your cardiac output is not what it should be when you exercise, even mild exercise like walking, you will feel shortness of breath that [may be due to] cardiovascular causes,” he says.

Heart conditions that can cause shortness of breath include having an enlarged heart, an abnormal heartbeat, or a heart attack.

Shortness of breath is a common symptom in people with congestive heart failure.

“In heart failure, the heart is not pumping strong enough and fluids back up, particularly in the lower extremities, but also in the lungs,” says Dr. Drake. “It feels as though you’re drowning.”

Talk to your doctor about your symptoms, and seek emergency medical attention if your shortness of breath comes on suddenly, is severe, and is accompanied by chest pain or other signs of a heart attack.

Being overweight or obese can aggravate certain types of asthma. “The heavier you are, the more likely you are to have asthma and more severe,” says Dr. Edelman.

But being overweight can make breathing hard for anyone, regardless of whether they have asthma, he adds. “Some of it is mechanical. 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, he says.

Shortness of breath is also a symptom of a condition called obesity hypoventilation syndrome (OHS). This is when inadequate breathing, due in part to pressure on the chest, lowers oxygen levels while raising carbon dioxide levels in the blood. Untreated, OHS can lead to heart trouble and even death.

Smokers may not realize that the habit is causing shortness of breath even if they haven’t been puffing for all that long.

“People are very, very good at denying symptoms, especially smokers who want to continue smoking and not admit they’re having problems,” says Dr. Edelman. “People will have some degree of shortness of breath but not recognize it. You learn to live with the symptoms.”

The longer you smoke, the worse this and other symptoms will become, possibly leading to COPD, lung cancer, and other conditions.

If you don’t smoke, don’t start. If you do smoke, quit. “You do get healthier over time if you quit,” says Dr. Edelman.

If you’re a former or current smoker, check out new lung cancer screening guidelines.

RELATED: 11 Home Remedies to Try When You Can’t Stop Coughing

Not surprisingly, different lung conditions can cause shortness of breath at different stages in their development.

“Virtually all diffuse lung disease can cause shortness of breath,” says Dr. Edelman. Diffuse lung disease is when the whole lung is affected.

Lung cancer is one particularly frightening example.

“The terrible thing about lung cancer is when it starts and when it’s in the stage that it’s curable, it [often] doesn’t cause symptoms because it’s localized,” says Dr. Edelman. “If it grows so large it blocks the airway, then you’ll get shortness of breath.” Unfortunately, clear symptoms also usually mean it’s harder to treat.

Other lung diseases that cause shortness of breath include tuberculosis and croup (both lung infections), pulmonary hypertension (a type of high blood pressure that affects the lungs), and pulmonary fibrosis (a condition that involves scarring of lung tissue).

Broken ribs on their own can cause shortness of breath along with piercing pain, but they can also puncture your lung and lead to a collapsed lung, also called a pneumothorax.

“With a collapsed lung ... it’s both pain and shortness of breath,” says Dr. Edelman. “If you suddenly get shortness of breath and severe pain, head to the emergency room.”

There’s no specific treatment for fractured ribs–you just have to let them heal–but doctors can take care of a collapsed lung. Observation and oxygen therapy may be all that's needed if only a small portion of the lung has collapsed; a needle or tube inserted into the chest can help when it's a larger portion. If that doesn’t work, surgery may be necessary.

Fractured ribs also raise the risk of pneumonia, especially among older people.

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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 ... in the setting of an acute anxiety attack,” says Dr. Drake.

Feeling short of breath can then make you feel more anxious, setting up a vicious cycle sometimes leading to outright panic.

Other common symptoms are heart palpitations, sweating, and having a feeling of impending doom.

Learn to manage anxiety with relaxation and deep breathing techniques (it helps expand your lungs so you breathe in more air), along with avoiding the things that trigger you. (A mental health professional can help you with this.) Limit caffeine and alcohol and avoid cigarettes, all of which can heighten anxiety.

RELATED: 19 Natural Remedies for Anxiety

Anemia, a common condition especially among women, can also cause shortness of breath.

“Your oxygen levels are OK, but there aren’t enough red blood cells carrying that oxygen,” explains Dr. Drake. That can also make you feel weak, tired, and dizzy.

Anemia can usually be treated, but treatment depends on what’s causing the problem. Iron supplements may help boost red blood cells in some people, as can eating more iron-rich foods like beef, beans, dark green leafy vegetables, dried fruit, and fortified cereals.

Other people may need medications or even surgery or blood transfusions. Anemia can also be caused by underlying conditions like cancer, rheumatoid arthritis, or HIV/AIDS.