Hello thank you for trusting HCM Dear both hyper and hypoglycemia may cause headache. Hyperglycemia headache:hyperglycemia, a headache can be a sign that you need to check your blood sugar. Other early signs of hyperglycemia include:fatigue blurry vision,excessive thirst and dehydration increased urination,excessive hunger,sores that won’t heal. Hypoglycemia headache:Low blood glucose, or hypoglycemia, is defined as having blood sugar levels below 70 mg/dL. Unlike hyperglycemia, the symptoms of hypoglycemia are typically sudden. present as dizziness,shakiness,excessive sweating sudden hunger,irritability,nausea,excessive fatigue weakness,anxiety or confusion. if your sugar levels is under control still suffering from headache then you may think about other causes of headache. it may be tension, migraine or occipital neuralgia etc.. just use tab.ultracet twice a day for five days. if symptoms not improved please consult your doctor he will examine and treat you accordingly. take care