How taking too many painkillers can make a headache worse

Photo by Nahi Khabar 24/7 – via Personal Collection

Many people reach for a pill at the first sign of head pain. That’s understandable — painkillers work, and they’re convenient. But when painkillers (both over-the-counter and prescription) are used too frequently for headaches, they can start causing a new, often daily, kind of headache known as medication-overuse headache (MOH) — formerly called “rebound headache.” This article explains how that happens, the warning signs, and what to do.

What is medication-overuse headache?

Medication-overuse headache is a secondary headache disorder that develops in people who repeatedly use acute headache treatments. It most commonly affects people who already have migraine or frequent tension-type headaches, and it may transform episodic headaches into chronic, near-daily pain. MOH is now recognized as one of the most common causes of chronic daily headache.

Which drugs cause it — and how often is too often ?

Almost any acute headache medication can trigger MOH if taken too often, including:

Simple analgesics (paracetamol/acetaminophen, aspirin), and NSAIDs (ibuprofen, naproxen).
Triptans and ergotamines (used specifically for migraine).
Opioids and combination drugs (e.g., butalbital-containing pills) — these carry the highest risk.

As a rule of thumb used by headache experts:

Using triptans, ergots or opioids on ≥10 days per month for >3 months risks MOH.
Using simple analgesics or NSAIDs on ≥15 days per month for >3 months risks MOH.
Exact thresholds vary by drug class, but repeated monthly use above these levels is a red flag.

Why do painkillers eventually make headaches worse?

The exact biology is complex and not fully understood, but major explanations include:

Neurochemical changes in pain regulation: Repeated short-term suppression of pain signals can alter the brain’s pain-modulating systems (including serotonin and dopamine pathways). Over time these adaptations lower the brain’s threshold for pain, so headaches become more frequent and harder to treat.
Reduced effectiveness of acute medicines: With overuse, the same medication produces less relief (tolerance). Patients take more or take it more often, which deepens the cycle.
Psychological and behavioral reinforcement: Frequent relief reinforces medication use; people learn to treat any minor head discomfort immediately with pills, preventing non-drug coping strategies and increasing dependence on medication.

Typical symptoms and signs

Headache occurring most days (often daily) or for ≥15 days per month.
Headache pattern that worsens over weeks to months despite — or because of — frequent medication use.
Medication gives short-term relief but headaches return as the drug wears off.
Some patients notice increased neck tightness, morning worsening, or that pain affects quality of life and sleep.

How is MOH diagnosed?

Doctors diagnose MOH based on history: frequent headaches and a pattern of regular use of acute headache medications above the risk thresholds for several months. Your clinician will review medication types, dosing frequency, headache diary entries, and rule out other causes before confirming MOH.

Treatment — breaking the cycle

The single most important step is stopping (or significantly reducing) the overused medication. That can be hard — headaches often spike at first — but many patients improve significantly within weeks to months after withdrawal.

Typical treatment steps:

Stop the overused drug (abruptly for most medications; gradual taper for opioids or barbiturate combinations).
Provide short-term bridge therapies if needed (anti-nausea meds, steroids or non-overused analgesics under supervision) to ease withdrawal headaches.
Start preventive therapy tailored to the underlying headache disorder (e.g., daily preventive migraine medications, lifestyle changes).
Follow up closely with a neurologist or headache specialist. Behavioral therapy and education help prevent relapse.

Prevention — safe use of painkillers

Limit acute headache medication to no more than 10–15 days per month, depending on the drug class. If you need pills that often, ask your doctor about preventive treatments.
Avoid chronic use of opioids or butalbital combinations for headache — these have a high risk of MOH and other harms.
Keep a headache and medication diary: track days with pain, severity, and what you took. That helps your clinician plan safer treatment.

When to see a doctor urgently

If headaches become daily or much worse over weeks.
If you’re taking acute headache meds more than 10 days a month (or 15 for simple analgesics).
If you’re using opioids or combination pills regularly.
If headaches are accompanied by new neurological symptoms (weakness, speech changes, confusion), seek immediate care.

Final note

Medication-overuse headache is common but preventable and treatable. If you suspect your painkiller use is causing more headaches, talk to a healthcare professional before making major changes — especially if you use opioids or complex combination drugs. A planned withdrawal and a preventive strategy can stop the cycle and restore better control of your headaches