Q: Whenever I raise my arms overhead for more than 30 seconds, my hands go numb. My mother thinks this could be the sign of a heart problem. Is she right?

A: Loss of circulation to the hands can occur with arms raised overhead from one of several different problems.

The onset of angina and a subsequent heart attack is known to be precipitated when working with the arms extended over the head.

Oxygen requirements of the heart are greater during arm work compared to leg work at the same workload level. If a person becomes weak or short of breath while in this position, ischemia (loss of blood supply) may be the cause.

Pain and numbness can also be the result of a condition known as thoracic outlet syndrome (TOS).
The main cause of TOS is that the nerves and blood vessels going from the neck down to the arm and hand get squeezed near the thoracic outlet. The thoracic outlet is this opening between the scalene muscles and the rib cage. The nerves and blood vessels go through the outlet opening, then under the collarbone (also known as the clavicle), through the armpit (the axilla), and down the arm to the hand.

There's a wide variety of reasons why you might develop TOS as a potential cause of your current symptoms. For example, pressure on nerves and vessels can happen in people who have fractured their clavicle. It can also happen in people who have an extra first rib, although this doesn't always result in TOS.

Extra muscle or scar tissues in the scalene muscles can put extra pressure on the nerves and arteries. Heavy lifting and carrying can bulk up the scalenus muscles to the point where the nerve and arteries get squeezed
Traumatic injury from a car accident can also cause problems that lead to TOS. In an accident, the shoulder harness of the seat belt can strain or tear the muscles. As they heal, scar tissue can build up, putting pressure on the nerves and blood vessels at the thoracic outlet.

Neck and arm positions used at work and home may contribute to TOS. People who have to hold their neck and shoulders in awkward alignment sometimes develop TOS symptoms. TOS symptoms are also reported by people who have to hold their arms up or out for long periods of time.

People with TOS often slouch their shoulders, giving them a drooped appearance. The poor body alignment of slouching can compress the nerves and arteries near the thoracic outlet. Being overweight can cause problems with posture, and women who have very large breasts may also have a droopy posture. For some reason, TOS affects three times as many women as men.

Regardless of the cause of your symptoms, this is something that should be evaluated by a medical doctor. An accurate diagnosis will guide treatment. Early discovery of the problem and early intervention usually results in improved outcomes. If it is something as serious as heart ischemia, you don't want to delay.

Reference: Richard M. Braun, MD. Thoracic Outlet Syndrome: A Primer on Objective Methods of Diagnosis. In The Journal of Hand Surgery. September 2010. Vol. 35A. No. 9. Pp. 1539-1541.