Chronic tension headache is a condition where you have a tension headache on at least 15 days every month for at least three months.This can be tiring and depressing. Tension headache (also called tension-type headache) is the common type of headache that most people have at some time.
It's not known exactly how common chronic tension headache is, as few studies have looked at this clearly. Some studies have estimated that around 1 in 30 of all adults have chronic tension headaches - which means they have a headache on more than half of all days for three months or more. However, it is possible that a proportion of these patients actually have developed medication-overuse headaches (medication-induced headaches) as a result of their tension headaches. Therefore, it can be difficult to be certain which is their main problem.
Chronic means persistent; it does not mean severe. The severity of the headaches can vary from mild to severe. Because of the persistent nature of the headaches, however, this condition is often quite disabling and distressing, and most patients take preventative medication.
This condition tends to develop in people who start off with having tension headaches with increasing frequency, until they occur on most days. However, the cause of the tension headaches is not always clear, and may be more than one thing. They may be due to tension in the muscles at the back of the head and neck, but it is now clear that this is not always the cause. Other causes reported by patients include stress, tiredness, hunger and eye strain. Many chronic tension headaches develop for no apparent reason. Working long hours bent over a computer may trigger them.
Some people get tension headaches if they drink too much caffeine or alcohol, if they don't drink enough water or if they go for a long time between meals and become tired and hungry. Occasionally, tension headaches can be caused by poor vision, particularly if reading in low light for long periods. Some may be triggered by environmental discomforts such as heat, cold, brightness or wind.
Some research suggests that your genetic make-up may be a factor. This means that some people may inherit a tendency to be more prone to develop tension headaches than others when stressed or anxious.
By definition, tension headaches are not caused by other conditions. So, if you have chronic tension headache, a doctor's examination will be normal apart from the muscles around the head perhaps being fairly tender when a doctor presses on them. Any tests that may be done will be normal.