Adrenaline increases the "alertness" of the nervous system, meaning it's ready to trigger muscle contraction. It also increases the amount of blood flow and changes the tension of the muscles, which, ...

Add Yahoo as a preferred source to see more of our stories on Google. You’re relaxing on the sofa when suddenly your eyelid starts twitching. Or perhaps it’s a muscle in your arm, your leg, or your ...

Muscle and joint pain may overlap, but they can have different causes and treatment approaches. Muscle and joint pain can accompany swelling, stiffness, reduced mobility, and other symptoms. This ...

To understand what causes muscle fatigue, it’s worth looking at what exactly muscle fatigue is. If you exercise regularly, you may be familiar with the sensation of a dull ache in your muscles or ...

Unexplained muscle pain in the arms and legs may be the result of benign issues. Or it may point to a more serious underlying condition, such as fibromyalgia, infection, or thyroid issues. Muscle pain ...