Whether a headache causes sudden death once you stay up late should be analyzed on a case-by-case basis. Headache after staying up late is often diagnosed as tension headache in clinical practice, but tension headache does not lead to sudden death, the cause of sudden death is due to staying up late. If you stay up late for a long time, the body’s muscles are always in a state of tension, which forms pressure on the nerves and leads to chronic soft tissue edema, which is the main reason for the formation of tension headache. In addition, when the body is extremely fatigued, causing sympathetic excitation, parasympathetic nerves are inhibited, the secretion of catecholamines and adrenaline hormones in the blood increases, which can initially manifest as reflex tachycardia. If you stay up late often, atrial or ventricular premature beats can occur, inducing malignant arrhythmias, which can lead to cardiac arrest and sudden death. Therefore, patients should ensure regular work and rest, avoid staying up late, ensure sufficient sleep time, avoid strenuous exercise before bedtime, and should not drink coffee and strong tea to ensure good sleep quality.