Shortness of Breath: Causes, Chest Pain & Health Risks

What causes shortness of breath when walking, biking, or lying down? From low blood oxygen levels to vitamin insufficiencies, identifying the triggers for respiratory distress in teens and the elderly is essential.

What May Cause Shortness of Breath When Walking or Biking?

Published Aug,14 2017 | By Dana Severson

Experiencing shortness of breath when walking or biking is likely caused by one of two things. You may reach your natural threshold for physical exertion, which leads to a shortness of breath.