What causes shortness of breath when lying down given that I’ve already been tested for blood pressure, stress, heart and lung failure and I passed them all? Could it be over exercising?

Shortness of breath when lying down is a condition known as orthopnea. It can be caused by a number of different factors, including lifestyle choices such as over-exercising. Other potential causes include heart failure and narrowed airways due to asthma or chronic obstructive pulmonary disease (COPD). You can also experience shortness of breath if you have fluid buildup in your lungs caused by pneumonia, congestive heart failure, or other illnesses.

It’s important to determine the underlying cause for any symptoms like this so that you can get proper medical treatment. Along with lifestyle changes like reducing exercise levels and quitting smoking (if applicable), your doctor may recommend medications or oxygen therapy to help relieve your symptoms. Some people find relief from using supplemental pillows while they sleep, taking frequent breaks when performing strenuous activity, and avoiding exposure to allergens which could contribute to breathing difficulties while resting.