The eight month old baby occasionally clenched his fist to make strength may be physiological phenomenon, may also be caused by disease, if accompanied by other abnormalities, it is recommended to consult a doctor in a timely manner, improve the examination to find out the cause of the disease. 1. physiological phenomenon: eight month old baby occasionally clenched his fist to make strength is generally a normal physiological phenomenon, such as about to defecate or to relieve fatigue, and so on. The baby’s age is small, the system development is not perfect, may be in the ordinary often clenched fists. So if there is no other discomfort, there is no need for special treatment, with the growth of the baby can disappear. 2. Diseases: diseases such as rickets, epilepsy and other diseases can lead to abnormalities in the nervous system, which can lead to eight-month-old babies occasionally clenching their fists to make strength. Can be accompanied by twitching of the limbs, easy to wake up, easy to cry, night sweats (abnormal sweating after falling asleep, waking up sweating stops) and other symptoms, the need for timely medical treatment, to be treated. If the eight-month-old baby occasionally clenched his fists to make strength, it is recommended to go to the hospital in time for relevant examinations, to avoid affecting the baby’s growth and development.