A hard bump on the back of the head may be a normal physiological structure, or it may be caused by trauma, cranial osteoma, sebaceous cysts and other factors.
1. Normal physiological structure: a hard bump in the middle of the back of the head may be caused by the protrusion of the occipital bone, there are large individual differences, some people protrude from the surface of the occipital bone, it will be more obvious, which belongs to the normal physiological structure.
2. Trauma: If the back of the brain is suddenly hit by external force or heavy objects, it may lead to the appearance of subcutaneous hematoma, and thus a hard bag appears on the back of the brain, accompanied by pain, redness and swelling and other symptoms.
3. Cranial osteoma: it is a lesion of cranial bone, belongs to benign tumor, often bulges on the bone surface, grows slowly, and usually has no other obvious symptoms.
4. Sebaceous cyst: it is a cyst formed due to the accumulation of gland contents after the local sebaceous gland ducts are blocked. The cyst is round and protrudes toward the skin surface, and if secondary infection occurs, the local skin can be red, swollen and painful.
There is a raised hard bag on the back of the head may also be caused by other factors, it is recommended that the patient seek medical attention in a timely manner, under the advice of the doctor, after the cause of the disease is clear targeted treatment.