Do you tend to have more headache days—other than migraine attacks—than pain-free days? If so, you may have medication overuse headache (MOH). Also called chronic daily headache or rebound headache, MOH occurs most often in people with a primary headache disorder such as migraine, cluster headache, or tension-type headache, according to the American Migraine Foundation. It’s caused by taking acute medications too often, although exactly what “too often” means can depend on the medication being taken. Medication overuse headache isn’t just annoying because you have near-constant head pain: MOH can also cause headaches that are resistant to migraine preventative medications, making acute treatments less effective. See what you need to know about medication overuse headache MOH

# 1. Medication overuse headache has a precise definition

The International Headache Society defines MOH as headache occurring 15 or more days per month in a person with a pre-existing primary headache disorder and developing as a consequence of regular overuse of acute or symptomatic headache medications for more than three months. Different medications have different guidelines for what constitutes overuse. According to the American Migraine Foundation, using triptans, ergot alkaloids, combination analgesics, or opioids for 10 or more days per month is considered abuse. Taking simple analgesics, including nonsteroidal anti-inflammatory drugs (NSAIDs) — a class of medications that includes aspirin, ibuprofen, and naproxen — on 15 or more days per month is also overuse. Medication overuse headaches usually resolve after the overuse is stopped, although patients may experience a period where their headaches get worse before they get better.

# 2. Frequency matters in headache in MOH and not the quality

Medication overuse headache can feel different to everyone. It is important to note that it does not matter whether it is located in front or behind, right or left, above or below, mild, moderate or severe. It is not the quality of the headache but the frequency that is of interest in this case. A characteristic feature of MOH is the frequency with which it occurs.

# 3. Every day with any type of headache counts as a “headache day”

If you are not sure if you are experiencing MOH, try keeping a diary and counting the number of headache days you have. Don't just count the days you have migraine attack symptoms, but all days with any type of headache. Alternatively, you can count the number of days you are certain are completely headache-free. How many days are crystal clear from the time you open your eyes until the time you go to bed at night, without a headache? Clear days should be at least 15 days a month to avoid chronic migraine.

# 4. Taking certain medications just once a week can make migraines worse

Certain types of medications that can be used for emergency relief of a migraine attack should be used with caution because of the risk of rebound headaches, according to the American Migraine Foundation. Opioids, also called narcotics, such as oxycodone and hydrocodone, can cause worsening or more frequent headaches when used weekly. These drugs alter the brain's pain-regulating systems in a negative way and not only make migraine attacks worse in terms of frequency, severity, and duration, but often make them untreatable.

# 5. Painkillers taken for any reason can lead to MOH

Taking painkillers for reasons other than migraines can cause MOH. For example, you could be taking a painkiller for back pain, the brain doesn't know the difference. Also, the frequency of use and the type of medication are related to conversion to MOH.

# 6. The more headache days you have, the greater your risk for chronic daily headache

The more headache days a person has, the more likely they are to develop chronic migraine. Studies done in both the general population and clinics show that people who have 10 to 14 headache days per month are 20 times more likely to develop daily headaches compared to people who have fewer than five headache days per month. The frequency of headache days is actually a big risk factor for development, and headache frequency is linked to how often someone reaches for an acute medication for treatment—although these are separate risks, they feed into each one. That's why we're trying so hard to reduce the total number of headache days per month, as well as the number of acute medication days per month.

# 7. Caffeine can contribute to medication overuse headaches

Caffeine at 100 to 200 milligrams (mg) per day is probably enough to contribute to a medication overuse headache. For reference, 8 ounces of coffee contains between 80 and 100 mg of caffeine, and 12 ounces of a caffeinated soft drink has between 30 and 40 mg, according to the Food and Drug Administration. Some headache medications also contain caffeine. It's best to cut back on caffeine, as long as it's not high-dose caffeine, to see if we can help them without taking away one of their pleasures.

# 8. Painkillers are not the only type of medication that can contribute to MOH

Over-the-counter decongestants and prescription sleeping pills can contribute significantly to MOH. There is some controversy among experts about whether benzodiazepines can cause medication overuse headaches. I personally believe they can interfere with treatment, so I don't prescribe them for my migraine patients. Even when they are anxious, I look for other treatments, he says.

# 9. MOH can be caused by excessive use of a combination of medications

The MOH medication guidelines are divided into different categories, but almost no one takes just one medication to treat migraines, Tepper says. You might have some days on triptans, some days on combination analgesics, some days on NSAIDs. It’s probably best to assume that if someone is taking 10 or more days of acute treatment per month, they are likely to develop medication overuse headache and turn into chronic migraine,” he says.

# 10. CGRP migraine treatments do not increase the risk of MOH

One type of medication for treating migraine, CGRP receptor antagonists, does not appear to cause a transformation to daily headache. Drugs that block CGRP are also used to prevent migraines. It is therefore vital that medication is supervised by a headache specialist and used as directed, as there are risks of headaches from overuse of medication.