A little pain in the back of the head may be caused by posture discomfort, occipital neuralgia, high blood pressure and other reasons. 1. Postural discomfort: if the patient looks down at the cell phone or computer for a long time or works for a long time, the incorrect posture for a long time may cause muscle spasms and lead to a bit of pain in the back of the head on the left side. 2. Occipital neuralgia: commonly secondary to cervical spine disease, spinal cord tumor, trauma, cervico-occipital myositis and so on. It manifests as a persistent dull pain at the back of the head, radiating to the top of the head and around the ears, and can be aggravated by paroxysms. 3. Hypertension: Hypertension patients with poor blood pressure control, resulting in increased intracranial pressure, may cause a little pain in the back of the head on the left side. The left back of the head a little pain may also be tension headache, scalp trauma and other causes, the patient should go to the regular hospital in a timely manner, to clarify the cause of the disease, and targeted treatment.