Having a constant mild headache on one side of your head for a year is something that should be evaluated by a doctor to determine the cause. Persistent headaches localized to one side can be due to several reasons such as tension-type headaches, migraines, or other neurological conditions.

• Since the headache has lasted this long and is localized, it is important to see a neurologist for a thorough assessment.
• They may recommend imaging studies or other tests to rule out underlying causes.
• Keep a headache diary noting frequency, intensity, triggers, and any associated symptoms to help your doctor.

If the headache worsens, is accompanied by vision changes, weakness, or confusion, seek urgent medical attention. Otherwise, scheduling an appointment with a neurologist is the best next step.To narrow down potential causes, we will need some more information.Please tell me your age and gender.