Most causes of shortness of breath are due to heart and lung conditions. Your heart and lungs are involved in transporting oxygen to your body and removing carbon dioxide, and problems with either of these processes affect your breathing.
According to Dr. Gabriel Omonaiye, breathing is regulated by the brain and a complex interaction between various chemicals in the blood and in the air that we breathe. Oxygen levels, carbon dioxide levels, and the amount of hemoglobin in blood play a role.
“If blood carbon dioxide levels rise, the brain tells the body to increase the breathing rate, which can result in deeper or faster breaths. This may lead to a sensation of difficulty breathing.”
Omonaiye noted that likewise, too much acid in the blood from an infection, lactic acid build-up or other causes can lead to an increase in the breathing rate and the sensation of shortness of breath. But there are also other medical conditions that cause shortness of breath.
Asthma
Asthma causes your airways to suddenly narrow and swell. You may struggle for air, cough up mucus, or hear whistling when you breathe. Some things could trigger an attack, including pollen, dust, smoke, exercise, a cold, and stress.
Your doctor can help you figure out what causes yours. He or she might prescribe medication for you to inhale during an attack to help you breathe more easily.
Allergies
Pollen, dust, and other things you breathe in can cause allergies. Sometimes the allergic reaction causes asthma. But it’s not always something in the air. It could start with something you touch, or some food you eat.
Talk with your doctor about how best to manage your asthma and allergies. Make sure to check in when your symptoms change, too.
Anxiety
You may breathe harder when you are scared or worried. It’s usually not a big deal, but it can be serious if you already have lung problems. Sudden stress, like a car accident, could trigger an attack if you have asthma. Even if you are otherwise healthy, anxiety might cause you to breathe fast enough to get lightheaded and pass out.
Carbon monoxide
It’s a colorless, odorless gas that can come from furnaces, fireplaces, water heaters, dryers, and car fumes. If it isn’t sent out the right way, it can build up in the air, and you could breathe too much of it. That makes it hard for your red blood cells to send oxygen through your body.
You may be short of breath, dizzy, confused, weak, and nauseated. Your vision could blur, and you could pass out. It could be life-threatening.
Cold
It happens thanks to a virus that causes a runny nose, sneezing, and sometimes fever. It may irritate your lungs and airway, and bring a cough that can make it hard to breathe. There’s no cure, but it usually gets better on its own in a week or so. See your doctor if you have high fever, if you are wheezing, or if it’s hard to catch your breath.
Pulmonary Embolism
A blockage, or clot, often in your leg, breaks loose, and a piece goes to your lung and blocks blood flow. That can make it hard or painful to breathe. You could feel faint, and your heart might race. Some people cough up blood. You may have swelling, warmth, and soreness where the clot started.
If any of this happens to you, get to the hospital, as it can be life-threatening. Your doctor may use blood thinners, other drugs, or surgery.
Sleep Apnea
It’s a condition when breathing stops repeatedly during sleep, so a person may not realize anything is happening. But you might be tired, groggy, and moody the next day. It could lead to high blood pressure and make you more likely to have heart disease and a stroke.
Extra weight is a risk. It may help to lose weight, but not all people with sleep apnea are overweight.
Pneumonia
A virus, bacteria, or fungus infects the air sacs inside your lungs. Then those sacs fill with fluid. This makes it harder to breathe. You also could have chills and fever, and you might cough up thick, colored mucus.
Check in regularly with your doctor. He or she might prescribe antibiotics if your pneumonia is caused by bacteria.
Heart Failure
It doesn’t mean your heart has failed, just that it’s not as strong at pumping blood as it should be. That makes it harder to get oxygen where it needs to go. Blood backs up in your lungs. That can make you short of breath.
Simple things like climbing stairs, walking a long way, or carrying shopping bags might tire you out. Your doctor can help you manage your symptoms.
Anemia
When your body doesn’t have enough healthy red blood cells, you can’t get enough oxygen to your tissues. That can make you weak and tired, and sometimes short of breath. It can also make you dizzy and pale, with cold hands and feet, and a fast heartbeat. Lots of things cause it, so treatment depends on what’s causing yours. Talk to your doctor if you are tired and can’t figure out why.
Collapsed lung
Doctors sometimes call it pneumothorax. It happens when an injury or disease causes air to leak from your lungs to the space between your lungs and the wall of your chest. The air pushes on the lung, making it fold in on itself. You could have chest pain and be short of breath. Your doctor may put a needle or small tube into the area to remove the air, or you may need surgery. But if it’s minor, it might get better on its own.
Broken heart
It’s a real thing. There’s even a name for it: broken heart syndrome. Sudden, intense emotion, a lost loved one or ended romance, for example affects the heart, causing sharp chest pain and making it hard to breathe. The heart doesn’t pump as well for a while. Unlike a heart attack, it doesn’t happen because your arteries are blocked. Most people get better within a few days or weeks.