Serum homocysteine is a blood test that indicates whether the patient is deficient in folic acid. If deficient or if the patient has elevated serum homocysteine, the patient is highly considered to be prone to stroke. If the patient also has hypertension, the patient is considered to have type H hypertension, which is hypertension with elevated homocysteine. Such people should take additional oral folic acid tablets along with antihypertensive drugs, but it is not recommended to take too large a dose, generally it is recommended to take 0.4-0.8mg daily, which can be taken orally for a lifetime. Patients should improve their dietary habits and eat more green leafy vegetables, which are rich in folic acid and help lower serum homocysteine levels.