Thigh pain at night may be related to physiological factors, chronic strain injury, calcium deficiency, lumbar spine disease and so on. 1. Physiological factors: too much exercise during the day, resulting in an increase in lactic acid within the thigh muscles, which cannot be metabolized in time and accumulates in the muscles, resulting in thigh soreness at night when you sleep. 2. Chronic strain injury: chronic strain injury of the thigh muscle exists, and if you do not pay attention to keep warm and get cold when you sleep at night, it may lead to the aggravation of the injury, and the symptoms of thigh pain will appear, and obvious pain will also appear when you press or exercise excessively. 3. Calcium deficiency: unbalanced diet, resulting in more calcium deficiency in the body, at night, leg cramps may occur, resulting in localized thigh pain. 4. Lumbar spine disease: such as lumbar disc herniation, in the evening when sleeping, sleeping posture is not appropriate, may lead to the nerves innervating the lower limbs are compressed and stimulated, can cause thigh pain, may also be accompanied by numbness of the lower limbs, lumbar pain and other symptoms. Repeated thigh pain at night, or accompanied by other clinical manifestations, it is recommended to seek medical examination and treatment as soon as possible.