Butt soreness at night can be caused by the following reasons: first, gluteus fasciitis, gluteus fasciitis is often due to strain or long-term bending and holding objects, resulting in chronic inflammation of the fascia, which can have the symptom of butt soreness when sleeping, and the pain increases in the morning, which should be diagnosed by early examination and examination to exclude other diseases. Secondly, when you get cold, you can also have the symptoms of buttock pain when you sleep at night, so you should get out of the cold environment early and pay attention to keep warm. Third, rheumatoid or ankylosing spondylitis, these two diseases can lead to symptoms of buttock pain when sleeping, can be accompanied by morning stiffness, can involve the entire spine, then we need to test blood and check the sacroiliac joint, lumbar spine x-ray to diagnose and early treatment. Fourth, pear-shaped muscle syndrome, patients with pear-shaped muscle syndrome can also have soreness in the pear-shaped muscle when sleeping, which can be accompanied by numbness and pain in the lower limbs, which should be diagnosed by early physical examination and electromyography of the nerves.