Classification of tension headaches

Tension-type headaches are classified as:¹

• Infrequent episodic. You may have infrequent episodic tension headaches if you have had at least 10 headaches that lasted less than 1 day each month (or less than 12 days of headache throughout the year). These headaches can last from 30 minutes to 7 days. The pain is mild to moderate and includes pressure or tightening across the forehead (like a "vise grip"), temples, back of head, or neck. The pain is felt on both sides of the head and sometimes is accompanied by sensitivity to light or noise (but not both together). Infrequent episodic tension headaches do not cause nausea or vomiting, and they do not get worse with physical activity.
• Frequent episodic. You may have frequent episodic tension headaches if you have had at least 10 headaches that lasted more than 1 day but less than 15 days each month for at least the last 3 months (or greater than 12 but less than 180 days a year with headache). These headaches can last from 30 minutes to 7 days. The pain is mild to moderate and includes pressure of tightening across the forehead (like a "vise grip"), temples, back of head, or neck. The pain is felt on both sides of the head, and sometimes you are sensitive to light or noise (but not both together). Frequent episodic tension headaches do not cause nausea or vomiting, and they do not get worse with physical activity.
• Chronic. You may have chronic tension headaches if you have had headaches on more than 15 days each month for at least 3 months (or more than 180 days a year with headache). The location of pain and pressure is the same as an episodic tension headache. But with chronic tension headaches, you may feel nausea (but without vomiting) along with being sensitive to light or noise. These headaches can sometimes be confused with migraine headaches. Chronic tension headaches may continue for days at a time and usually do not get better when you use pain relievers. Although the pain may be mild to moderate, the continual pain can become disabling. Often chronic tension headaches are related to an underlying problem with anxiety or depression.