NDPH occurs when someone rather suddenly has the onset of daily headache; the headache is usually a mixture of tension and migraine type features. The headache may start over hours or one day, often in someone with no previous serious history of headache. While we know that chronic daily headache occurs in about 3.5% of the population, we are not sure of the true incidence of NDPH. It is probably underestimated in studies.
Many with NDPH experience rather mild, or moderate, headaches that go away in months or 1 or 2 years with little treatment. However, in others the headaches are moderate to severe, last years, and are relatively refractory to treatment. Our usual therapies for migraine patients work better than for those with NDPH. Women are probably more likely to have NDPH, from age 15 to 30(possibly with an older age of onset, on average, in men). Most experience 24/7 headaches, with migraine features(nausea,sensitivity to light or sound, lightheadedness,dizziness, neck pain, visual disturbances(primarily blurring), and sensitivity to smells). Throbbing and pressure are the usual pain characteristics, often bilateral(both sides of the head).
The reasons for NDPH are unclear; many patients note an antecedent flu-like or viral illness. Epstein Barr Virus may be impolicated in some. Stress, mild head injury, and toxic exposures have also been implicated. In future blogs I will talk about treatment.