Question: what are the causes of headaches

Reference:
 Rebound headaches Overview Rebound headaches (medication-overuse headaches) are caused by regular, long-term use of medication to treat headaches, such as migraine. Pain relievers offer relief for occasional headaches. But if you take them more than a couple of days a week, they may trigger rebound headaches. It appears that any medication taken for pain relief can cause rebound headaches, but only if you already have a headache disorder. Pain relievers taken regularly for another condition, such as arthritis, have not been shown to cause rebound headaches in people who never had a headache disorder. Rebound headaches usually stop when you stop taking the pain medication. It's tough in the short term, but your doctor can help you beat rebound headaches for long-term relief. Symptoms Signs and symptoms of rebound headaches may differ according to the type of original headache being treated and the medication used. Rebound headaches tend to: - Occur every day or nearly every day, often waking you in the early morning - Improve with pain relief medication but then return as your medication wears off Other signs and symptoms may include: - Nausea - Listlessness - Restlessness and difficulty concentrating - Memory problems - Irritability When to see a doctor Occasional headaches are common. But it's important to take your headaches seriously. Some types of headaches can be life-threatening. Seek immediate medical care if your headache: - Is sudden and severe - Accompanies a fever, stiff neck, rash, confusion, seizure, double vision, weakness, numbness or difficulty speaking - Follows a head injury - Gets worse despite rest and pain medication - Is a new type in someone older than 50 - Wakes you from sleep Consult your doctor if: - You usually have two or more headaches a week - You take a pain reliever for your headaches more than twice a week - You need more than the recommended dose of over-the-counter pain remedies to relieve your headaches - Your headache pattern changes - Your headaches are getting worse Causes Rebound headaches can develop if you frequently use headache medication. Although the risk of developing medication-overuse headache varies depending on the medication, any acute headache medication has the potential to lead to rebound headaches, including: - Simple pain relievers. Common pain relievers such as aspirin and acetaminophen (Tylenol, others) may contribute to rebound headaches - especially if you exceed the recommended daily dosages. Pain relievers such as ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve) have a low risk of contributing to medication-overuse headaches. - Combination pain relievers. Over-the-counter (OTC) pain relievers that combine caffeine, aspirin and acetaminophen (Excedrin, others) are common culprits. This group also includes prescription medications such as Fiorinal, which contains the sedative butalbital. Butalbital-containing compounds have an especially high risk of causing rebound headaches, so it's best not to take them to treat headaches. If you do take this type of drug, limit its use to no more than four days a month. - Migraine medications. Various migraine medications have been linked with rebound headaches, including triptans (Imitrex, Zomig, others) and certain ergots - such as ergotamine (Ergomar, others). These medications have a moderate risk of causing medication-overuse headaches. The ergot dihydroergotamine (D.H.E. 45) appears to have a lower potential for leading to this problem. - Opiates. Painkillers derived from opium or from synthetic opium compounds include combinations of codeine and acetaminophen (Tylenol with Codeine No. 3 and No. 4, others). These medications have a high risk of causing rebound headaches. Daily doses of caffeine - from your morning coffee, your afternoon soda, and pain relievers and other products containing this mild stimulant - may fuel rebound headaches, as well. Read product labels to make sure you're not wiring your system with more caffeine than you realize. Risk factors Risk factors for developing rebound headaches include: - History of chronic headaches. A history of migraines, tension-type headaches or other chronic headaches puts you at risk. - Frequent use of headache medications. Your risk increases if you use combination analgesics, ergotamine or triptans 10 or more days a month or simple analgesics more than 15 days a month - especially if this regular use continues for three or more months. Diagnosis The diagnosis of rebound headache usually is based on a history of chronic headache and frequent use of medication. Testing usually isn't necessary. Treatment To break the cycle of rebound headaches, you'll need to restrict your pain medication. Depending on the drug you're taking, your doctor may recommend stopping the medication right away or gradually reducing the dose. Breaking the cycle When you stop your medication, expect your headaches to get worse before they get better. Drug dependency may be a risk factor for drugs that result in rebound headaches, and you may have withdrawal symptoms such as nervousness, restlessness, nausea, vomiting, insomnia or constipation. These symptoms generally last from two to 10 days, but they can persist for several weeks. Your doctor may prescribe various treatments to help alleviate headache pain and the side effects associated with drug withdrawal. This is known as bridge or transitional therapy, and treatments may include nonsteroidal anti-inflammatory drugs, corticosteroids or dihydroergotamine, an ergot often given through a vein (intravenously). Hospitalization Sometimes it's best to be in a controlled environment when you stop taking pain medication. A short hospital stay may be recommended if you: - Aren't able to stop using pain medication on your own - Have other conditions, such as depression or anxiety - Are taking high doses of drugs that contain opiates or the sedative butalbital - Are abusing substances such as tranquilizers, opioids or barbiturates - Have limited or no family support Preventive medications After you've broken the rebound-headache cycle, continue to work with your doctor to avoid relapsing and to find a safer way to manage your headaches. During or after withdrawal, your doctor may prescribe any of the following daily preventive medications: - A tricyclic antidepressant such as amitriptyline or nortriptyline (Pamelor) - An anticonvulsant such as divalproex (Depakote), topiramate (Topamax, Qudexy XR, Trokendi XR) or gabapentin (Gralise, Neurontin) - A beta blocker such as propranolol (Inderal, Innopran XL) - A calcium channel blocker, such as verapamil (Calan, Verelan, others) These medications can help control your pain without risking rebound headaches. If you're careful, you may be able to take a medication specifically meant for pain during future headache attacks. Be sure to take medications exactly as prescribed. Cognitive behavioral therapy (CBT) During this talk therapy, you learn ways to cope with your headaches. In CBT, you also work on healthy lifestyle habits and keeping a headache diary. Alternative medicine For many people, complementary or alternative therapies offer relief from headache pain. However, not all complementary or alternative therapies have been studied as headache treatments, and others need further research. - Acupuncture. This ancient technique uses fine needles to promote the release of natural painkillers and other chemicals in the central nervous system. There is some evidence that it can help control headaches and other conditions that cause chronic pain. - Biofeedback. Biofeedback teaches you to control certain body responses that help reduce pain. During a session, you're connected to devices that monitor and give you feedback on body functions, such as muscle tension, heart rate and blood pressure. You then learn how to reduce muscle tension and slow your heart rate and breathing to help you relax, which may help you cope with pain. - Herbs, vitamins and minerals. Some dietary supplements - including magnesium, feverfew and butterbur - seem to help prevent or treat some types of headaches, but there's little scientific support for these claims. If you're considering using supplements, check with your doctor. Some supplements may interfere with other drugs you take or have other harmful effects. Discuss the risks and benefits of complementary therapy with your doctor. 

Answer: Rebound headaches are caused by regular, long-term use of medication to treat headaches, such a pain relievers. If you take them more than a couple of days a week, they may cause rebound headaches. Rebound headaches usually stop when you stop taking the pain medication.