Weakness is a loss of muscle strength. If you have weakness, you can’t move a muscle normally, even when you’re trying as hard as you can. Weakness is different than being tired (fatigued), having stiff muscles, or not being able to move part of your body because it hurts too much to move.
Go to the emergency department right away if you have muscle weakness and any of these warning signs:
Call your doctor if you have muscle weakness without any warning signs so your doctor can decide how quickly to see you.
Weakness all over your body usually has different causes than weakness that's just in certain muscles.
If you have weakness all over your body, common causes are:
If you have weakness just in certain muscles, common causes are:
Doctors will ask questions about your weakness. They’ll do a physical exam to check for problems with your brain, spinal cord, nerves, and muscles, and to make sure you’re breathing well.
Depending on what doctors think is causing your weakness, they may do tests (see Diagnosis of Brain, Spinal Cord, and Nerve Disorders). These tests may include: