Regular exercise can help you control your weight, build cardiovascular fitness and help control your blood pressure. During exercise, however, your blood pressure rises slightly, which might be affecting your left jugular vein. The problem might go away once your body gets used to your new, more intense exercise regimen, but it's best to consult a doctor to rule out an underlying medical disorder.
The Jugular Vein
The jugular veins are located on both sides of the neck and are responsible for moving deoxygenated blood from the head down to the heart. You have two pairs of jugular veins, referred to as the internal and external jugular veins. The external jugular vein is closest to the skin and is the vein you can see bulging. A bulging vein means the pressure in the vein is increased, which can be caused by a variety of issues.
Exercise helps build cardiovascular fitness by working your heart muscle and increasing your lung capacity, which can ultimately help lower your blood pressure. However, when you are exercising, your blood pressure rises slightly due to the increased blood flow caused by your rapid heartbeat. This increased blood pressure can cause veins to engorge, particularly if the vein has a defective valve — which is the part of the vein that helps control blood flow. Exercise can also exacerbate other blood flow issues, leading to a bulging jugular vein.
Possible Causes of Bulging
In addition to a possible problem with your jugular valve, a bulging jugular vein — medically referred to as jugular vein distention — can also be caused by a variety of problems with your heart, such as congestive heart failure, or problems with the veins with which the jugular vein connects. Other issues that block blood flow from the jugular, such as a structural issue with the muscle or bone, can create a similar bulging.
If you experience a distended jugular vein only when you are exercising, consult a doctor as soon as you can to verify an underlying medical problem is not the cause. Not all left jugular vein distention is cause for concern, but the distention could be the beginning sign of a more serious medical problem. If you experience other symptoms along with the distended jugular vein, including chest pain, cold fingers or palpitations of the heart, seek immediate medical attention.