What can cause a muscle twitch in upper left leg?

Many things. Muscle twitches are involuntary spasms that in the great majority of people are benign. Stay hydrated, stretch before exercising, and eat a balanced diet. If other symptoms like weakness or numbness also develop, then you need to see your doctor.

Related Questions

Massive pain isolated in middle of back. Constant muscle twitching all over body primarily in legs. Weakness in left leg and arm. Mri of neck normal?

Back pain. There is concern for spinal cord damage in your thoracic spine and an MRI is needed of the thoracic spine immediately. Pressure on the spinal cord can cause irreversible damage including paralysis. Please go to the ER. Read more...

I left strenght training 3 months ago. Now there are muscle twitching in my whole body, no weakness, no atrophy. But nowthere are pins & needle (leg)?

One possibility.. Although rare, there is a neurologic condition, benign fasciculation syndrome characterized by twitches, cramping, tingling without weakness (that is a quick summary). See a neurologist or a physiatrist for evaluation to be sure. Whether it is this or something else, physical exam can reveal a lot. It could be a simple electrolyte imbalance. If neurologic, the nerves can be tested easily. Read more...