The possible causes of back pain after a night’s sleep include cold, lumbar muscle strain, cervical spondylosis, myofasciitis, ankylosing spondylitis, and so on. 1. Cold: It may be that you don’t cover up well after falling asleep at night, causing your back to catch a cold, which induces inflammation of the ligaments and muscles of your back, resulting in the symptom of sleeping overnight with a sore back. 2. Lumbar muscle strain: may be because the mattress is relatively soft, sleep at night when the muscles of the lower back is not fully supported, can not get enough rest, resulting in lumbar muscle strain strain. Or because of recent work, labor and other large, resulting in overwork, fatigue, sleep overnight back muscle pain. 3. Cervical spondylosis: sleeping overnight back pain may also be caused by cervical spondylosis, because the cervical disc bulge after the compression of the vertebral artery and nerve roots, may be manifested as back pain, numbness of the upper limbs, or even weakness of the upper limbs. 4. Myofasciitis: sleeping overnight back pain, may be because the back muscles, fascia, ligaments and other soft tissues are damaged, resulting in aseptic inflammation, resulting in myofasciitis. Inflammation stimulates the back muscles and produces spasms and soreness. 5. Ankylosing spondylitis: a typical symptom of ankylosing spondylitis is back pain and lumbosacral pain at night, and the pain will be alleviated in the morning through appropriate activities of the lumbar and back. Back pain after a night’s sleep may also have other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.