Your hands may seem weak if they are overtired (fatigued) from too much activity. Stop, change, or take a break from your activities, and your symptoms will usually get better or go away.

Muscle weakness that occurs in one area of your body with a loss of function, even for a few minutes, is a medical emergency. It may be caused by decreased blood flow to the brain. Causes of decreased blood flow to the brain include:

• A transient ischemic attack (TIA), which results in a brief and temporary loss of function.
• A stroke, which results in a progressive and permanent loss of function. Call 911 or other emergency services immediately if you think you are having a stroke.

Decreased movement may be caused by swelling. When the swelling goes down, normal movement should return.

Decreased movement or strength in your fingers, hands, or wrists may be caused by many health conditions.

• Tendinitis is actually a symptom of tendinosis, a series of very small tears (microtears) in the tissue in or around the tendon. In addition to pain and tenderness, common symptoms of tendon injury include decreased strength and movement in the affected area.
• Osteoarthritis is the progressive breakdown of the tissue that protects and cushions joints (cartilage). It may cause stiffness and pain with movement.
• Carpal tunnel syndrome is caused by pressure on a nerve (median nerve) in the wrist. The symptoms include tingling, numbness, weakness, or pain of the fingers and hand. See an illustration of carpal tunnel syndrome.
• Dupuytren's disease is an abnormal thickening of tissue beneath the skin in the palm of the hand or hands and occasionally the soles of the feet. The thickened skin and tendons (palmar fascia) may eventually limit movement or cause the fingers to bend so that they cannot be straightened. See an illustration of Dupuytren's contracture.
• De Quervain's disease is swelling and inflammation of the tendons and the tendon covering (sheath) on the thumb side of the wrist. The exact cause of de Quervain's disease is not known. It may occur from injury to the wrist or tendon or as a result of activities that require repeated wrist and thumb movements, such as knitting, wringing clothes, or lifting heavy objects.