Involuntary contraction of the muscles - a fairly common phenomenon. It happens among people of different ages and the causes can be different. Cause this kind of behavior of muscles nerves and the signals they give. Or the muscles from overexertion respond in a similar way to any movement of the limb.
Similar issues were dealt with by neurologists, but to run to the doctor immediately is not necessary. Think about whether your life stress lately. Emotional experiences affect the entire body, including your muscles. If stress has taken place, pass a course of treatment sedative drugs of natural origin, take tincture of Valerian, motherwort or "Novopassit". Try less nervous, drink some coffee and alcohol. Get plenty of rest and sleep for 7-8 hours.
The lack of potassium in the body can also cause twitching of the limbs. Submit to a blood test and refer the result to the doctor. You may have to take medication that contains a missing element.
Remember if a strong stress on the muscles of the limb with which the problems started. Lifting, stretching, straining during sports - all this can be reflected in the subsequent days on hand. Purchase a warming ointment, spread hand and wrap with a scarf. Try not to strain the arm for a few days.
If twitches become for you habitual, continuing for a long time and recur frequently, it makes sense to address to the neuropathologist. Describe all of the symptoms clearly indicate a time frame. After some issues clarifying the nature and examination, the doctor will make a diagnosis and prescribe treatment. Note that a similar phenomenon can cause drugs, so tell your doctor about all medications (including vitamins and Supplements) that you took in the last two months.