Hello whats the most common causes of shortness of breath 20 year olds. ive read asthma and anxiety would be on the top and less common is heart?

Yes, also: Asthma and anxiety are common causes of shortness of breath (SOB) in 20 year olds. Of course feeling SOB can make you feel anxious. If you have asthma you often make wheezing sounds. Heart problems generally don't cause SOB unless you have heart failure which is very rare in 20 yo's. Infections like bronchitis and pneumonia and Babesiosis (an infection most docs never consider) can also cause SOB.

Shortness of Breath: I commend you for your desire to care for your Health. At age 20, Anxiety is a common cause for Shortness of Breath. Respiratory conditions like Asthma, Viral infections or Bacterial infections can cause breathing difficulty; Cardiac conditions are less likely to cause it. Feel the Blessings of 3 million Air Sacs in your lungs! Do Breathing and Music Relaxation, Meditation, Yoga See a Physician