See a doctor if you have any of the following conditions:

• Any serious medical condition like diabetes, asthma, emphysema, cancer, or a history of blood clots in your legs or lungs.
• Pain or pressure in the chest, neck, shoulder, or arm during or right after activities such as walking.
• Bone or joint problems, including arthritis or osteoporosis (especially arthritis that has flared up so that one or more of your joints is red, swollen, or painful).
• A heart condition, angina (chest pain), high blood pressure, or high cholesterol.

Also, see a doctor if any of the following apply to you:

• Over age 40 or 45, and have not been active.
• Feel very breathless after mild activity.
• Tend to get dizzy, lose consciousness, or are subject to falls.
• Have experienced a feeling of your heart racing, skipping, or fluttering.
• Have had recent surgery, particularly to the eye or hip.
• Have an active infection or fever.
• Are experiencing any other unusual symptoms, such as unexplained weight loss
• You smoke.