Headache and nausea: causes, types, and when to see a doctor

1. Tension headaches

The most common type of headache. The pain is a dull, constant pressure around the head, often described as a tight band rather than a throbbing or pulsing sensation. It typically affects both sides of the head and can extend to the neck and shoulders.

Common causes: emotional stress, poor posture (particularly desk work), eye strain, jaw clenching, muscle tension in the neck and shoulders, fatigue.

What helps: over-the-counter painkillers (paracetamol or ibuprofen), applying heat or cold to the neck and shoulders, stretching, reducing screen time, and addressing the underlying stress or posture issue. If tension headaches become frequent (more than 15 days a month), see a doctor. Chronic tension headaches may need a different treatment approach.

2. Dehydration headaches

When your body loses more fluid than it takes in, the brain can temporarily contract, pulling away from the skull and triggering a headache. The pain can be mild or severe and is often accompanied by thirst, fatigue, dark urine, and dizziness.

What helps: drink water gradually rather than all at once. If you're regularly getting dehydration headaches, you're probably consistently under-hydrating. Most adults need 1.5 to 2 litres of fluid daily, more in hot weather or during exercise.

3. Exertion headaches

A headache that comes on during or immediately after physical activity: running, lifting weights, or any intense effort. The pain is usually throbbing and affects both sides of the head. It typically lasts between 5 minutes and 48 hours.

What helps: warming up properly before exercise, staying hydrated, and avoiding intense activity in extreme heat. If exertion headaches are frequent or severe, see a doctor to rule out underlying causes. Occasionally, exercise-induced headaches can signal a vascular issue.

4. Cold and flu headaches

A headache during a cold or flu is caused by your body's immune response, not the virus itself. When you're fighting an infection, your body releases cytokines (inflammatory proteins), which can trigger headache pain alongside the usual cold symptoms: sore throat, congestion, cough, and fatigue.

What helps: rest, fluids, and paracetamol or ibuprofen. The headache resolves as the infection clears. If your headache persists after the cold has gone, or is accompanied by facial pressure and coloured nasal discharge, you may have developed a sinus infection (see below).

5. Hangover headaches

Alcohol irritates the blood vessels in the brain, causes dehydration, and triggers an inflammatory response. The result is the familiar throbbing headache, often accompanied by nausea, fatigue, and sensitivity to light.

What helps: water (before, during, and after drinking), food, rest, and time. Paracetamol is gentler on the stomach than ibuprofen if you're feeling nauseous. The only reliable prevention is moderate alcohol intake.

6. Stomach flu headaches

Gastroenteritis (the stomach flu) causes vomiting and diarrhoea, which leads to dehydration, which causes headaches. The combination of fluid loss, fever, and fatigue can make these headaches particularly unpleasant.

What helps: oral rehydration solutions (not just water; you need to replace electrolytes), rest, and small sips of fluid even if you're vomiting. Most stomach flu resolves within a few days. If symptoms persist beyond 3-4 days, or you can't keep fluids down at all, see a doctor. Prolonged dehydration can become serious.

7. Sinus headaches

Pain and pressure around the forehead, cheeks, and eyes, worsening when you bend forward. True sinus headaches are caused by infection or inflammation of the sinuses (sinusitis). They're often accompanied by nasal congestion, thick nasal discharge, and sometimes fever.

Worth knowing: sinus headaches are one of the most commonly self-misdiagnosed headache types. Many people who think they have sinus headaches actually have migraines. If your "sinus headaches" don't respond to decongestants and come with nausea or light sensitivity, consider whether migraine is the real cause.

What helps: steam inhalation, decongestants, nasal irrigation. If the cause is a bacterial sinus infection, antibiotics may be needed. Recurrent sinus headaches can be caused by nasal polyps or a deviated septum, both of which are treatable.

8. TMJ headaches

The temporomandibular joint (TMJ) connects your jawbone to your skull. If this joint is stressed, misaligned, or inflamed, it can cause headaches that radiate from the jaw to the temples and around the ear. You may also notice clicking or popping when you open your mouth, difficulty chewing, or jaw stiffness.

Common causes: teeth grinding (bruxism), jaw clenching (often stress-related), bite misalignment, arthritis in the joint.

What helps: a bite guard or night guard (your dentist can custom-fit one), stress management, avoiding hard or chewy foods during flare-ups, and physiotherapy for the jaw muscles. If over-the-counter guards don't help, see your dentist for a custom appliance.

9. Seasonal allergy headaches

When pollen counts rise or the seasons change, airborne allergens can trigger nasal congestion, sinus pressure, watery eyes, sneezing, and headache. The headache is caused by inflammation and congestion in the sinus passages.

What helps: antihistamines, nasal corticosteroid sprays, and avoiding known triggers where possible. If seasonal allergies significantly affect your quality of life, your doctor can discuss longer-term management including immunotherapy (desensitisation injections).

10. Oversleeping headaches

Sleeping significantly more than your usual amount can trigger a headache. The exact mechanism isn't fully understood, but it's likely related to disrupted neurotransmitter levels (particularly serotonin) caused by altered sleep patterns.

What helps: keeping a consistent sleep schedule, even on weekends and holidays. Aim for 7-8 hours. Avoid the temptation to "catch up" with very long lie-ins.

11. Caffeine withdrawal headaches

If you regularly drink coffee, tea, or energy drinks and suddenly stop, you can expect a headache within 12-24 hours. Caffeine narrows blood vessels in the brain; when you withdraw it, the vessels dilate, causing a throbbing headache that can last several days.

What helps: if you want to reduce caffeine intake, taper gradually rather than stopping abruptly. Cutting by one cup every few days is usually manageable. If you're in the middle of withdrawal, the headache will pass within a few days.

12. Sexual activity headaches

Headaches triggered by sexual activity, typically during arousal or at orgasm. They're usually a dull ache that builds during sex or a sudden, intense headache at climax. They're more common in men and are generally benign, resolving on their own within minutes to hours.

When to be concerned: a sudden, severe headache during orgasm that feels unlike anything you've experienced before should be assessed urgently. In rare cases, this can indicate a subarachnoid haemorrhage. If the headaches are recurrent and follow a consistent pattern, they're almost certainly benign, but mention them to your doctor for reassurance.

13. Migraine

A migraine is more than a bad headache. It's a neurological condition that typically causes intense, throbbing pain on one side of the head, lasting anywhere from 4 to 72 hours. Nausea and vomiting are common. So is sensitivity to light, sound, and sometimes smell.

Some people experience an "aura" before the headache begins: visual disturbances such as flashing lights, zigzag lines, or blind spots, or physical symptoms like tingling in the hands or face.

Common triggers: stress, hormonal changes (particularly menstruation), certain foods (aged cheese, chocolate, alcohol, processed meats), disrupted sleep, bright or flickering lights, strong smells, weather changes.

What helps: during an attack, rest in a dark, quiet room. Over-the-counter painkillers (taken early) can help mild migraines. For moderate to severe migraines, prescription triptans are the standard treatment. If you're getting migraines frequently (more than 4-5 per month), preventive medication may be appropriate.

If you're experiencing frequent migraines, a GP consultation can help identify your triggers and put together a treatment plan. Book a same-day appointment at Medical Express Clinic: call 020 7499 1991.

14. Mononucleosis headaches

Mononucleosis (glandular fever) is a viral infection spread through saliva, most common in teenagers and young adults. Symptoms include severe sore throat, swollen lymph nodes, fever, extreme fatigue, and headache.

What helps: rest, fluids, and paracetamol or ibuprofen. There's no specific antiviral treatment. Recovery typically takes 2-4 weeks, though fatigue can persist for months. Diagnosis requires a blood test.

15. Fibromyalgia headaches

Fibromyalgia is a chronic condition characterised by widespread pain, fatigue, sleep problems, and cognitive difficulties. Headaches are common in fibromyalgia patients, often triggered by muscle tension and spasms in the neck and upper back.

What helps: if you've been diagnosed with fibromyalgia and experience frequent headaches, discuss this with your doctor. Treatment may include physiotherapy, medication for muscle tension, and management of sleep quality. The headaches rarely respond well to painkillers alone because the underlying cause is muscular and neurological.

16. Diet and blood sugar headaches

Skipping meals causes blood sugar to drop, which can trigger a headache. This is particularly common during restrictive dieting, fasting, or irregular eating patterns. Certain foods can also trigger headaches in susceptible people: aged cheese, processed meats, MSG, artificial sweeteners, and excessive sugar or salt.

What helps: eat regular meals at consistent times. If you're dieting, eat smaller portions more frequently rather than cutting meals entirely. If you suspect certain foods trigger your headaches, keeping a food diary for a few weeks can help identify patterns. Magnesium deficiency is another potential cause; speak to your doctor before supplementing.

17. Pregnancy headaches

Headaches are common throughout pregnancy, particularly in the first and third trimesters. Hormonal changes, increased blood volume, fatigue, dehydration, and stress all contribute.

When to be concerned: a severe headache in the second or third trimester, especially with visual disturbances, upper abdominal pain, or sudden swelling in the face or hands, can be a sign of pre-eclampsia. This is a serious condition that requires immediate medical assessment. Contact your midwife, GP, or maternity unit urgently.

What helps: paracetamol is generally considered safe during pregnancy. Avoid ibuprofen and aspirin unless specifically prescribed. Stay hydrated, rest when possible, and mention recurring headaches to your midwife or obstetrician.

18. Menopause headaches

Fluctuating oestrogen levels during perimenopause and menopause can trigger or worsen headaches. Some women who've had menstrual migraines find they improve after menopause; others find headaches become more frequent or change in character.

What helps: if menopause is triggering frequent headaches, discuss this with your doctor. Hormone replacement therapy (HRT) can help some women, though the type and delivery method matter (patches tend to cause fewer headaches than oral HRT). A full hormone profile can help clarify what's happening; our Advanced MOT (£999) includes a comprehensive female hormone panel.

19. Cluster headaches

Cluster headaches are one of the most painful headache types. The pain is severe, usually on one side, often centred around or behind one eye. Attacks last between 15 minutes and 3 hours and can occur multiple times a day for weeks or months (a "cluster period"), then disappear for months or years.

Associated symptoms: red or watering eye on the affected side, drooping eyelid, blocked or runny nose on one side, restlessness (unlike migraine, where lying still helps, cluster headache sufferers often pace or rock).

What helps: standard painkillers are too slow to help cluster headaches. Prescription treatments include high-flow oxygen therapy and injectable sumatriptan. If you think you're experiencing cluster headaches, see a doctor for a proper diagnosis and treatment plan. These headaches are frequently misdiagnosed as migraine or sinusitis.

20. Wisdom teeth headaches

Impacted or erupting wisdom teeth can cause referred pain to the jaw, temple, and ear, resulting in headaches. If a wisdom tooth is pushing against adjacent teeth or causing your bite to shift, the resulting jaw tension can also trigger TMJ-type headaches.

What helps: if you've recently had wisdom teeth removed, prescribed painkillers should manage the headaches during healing. If your wisdom teeth are still in place and you're getting jaw pain and headaches, see your dentist for an X-ray to assess whether extraction is needed.

21. Encephalitis

Encephalitis is inflammation of the brain, usually caused by a viral infection. Symptoms develop over hours to days and include sudden severe headache, high fever, extreme sensitivity to light, confusion, drowsiness, seizures, and muscle weakness.

What to do: go to A&E immediately. Encephalitis can cause permanent brain damage if not treated quickly. Treatment typically involves antiviral medication and hospital admission.

22. Meningitis

Meningitis is an infection of the membranes surrounding the brain and spinal cord, caused by bacteria, viruses, or fungi. Early symptoms include headache, nausea, fever, and a general feeling of being unwell. As the condition progresses, symptoms include severe neck stiffness, aversion to bright light, a distinctive non-blanching rash (in bacterial meningitis), cold hands and feet, and confusion.

What to do: call 999 or go to A&E immediately. Bacterial meningitis can be fatal within hours. Viral meningitis is generally less severe but still requires medical assessment. Some forms of meningitis are preventable by vaccination.

23. Brain tumour

A persistent or worsening headache that doesn't respond to normal painkillers, particularly one that's worse in the morning or when lying down, can occasionally indicate a brain tumour. Other warning signs include new-onset seizures, progressive weakness or numbness, changes in vision, speech difficulty, personality changes, or unexplained vomiting.

What to do: see a doctor. Most headaches are not caused by brain tumours, and anxiety about this possibility is extremely common. But a headache that is progressively worsening, unlike your usual headaches, and accompanied by neurological symptoms does warrant assessment. Your doctor can arrange appropriate imaging.

24. Brain abscess

A brain abscess is a rare but serious condition where a pocket of infected pus forms in the brain, usually from a bacterial or fungal infection. Symptoms include a persistent, worsening headache (often localised to one area), fever, confusion, seizures, and neurological symptoms depending on the abscess location.

What to do: seek urgent medical attention. Standard painkillers will not relieve headaches caused by a brain abscess. Treatment involves antibiotics and, in many cases, surgical drainage.

25. Thunderclap headache

A thunderclap headache reaches maximum severity within seconds. There's no gradual build-up. It's often described as "the worst headache of my life." This type of headache can indicate a subarachnoid haemorrhage (bleeding around the brain), cerebral venous thrombosis, or other vascular emergencies.

What to do: call 999 or go to A&E immediately. A thunderclap headache is a medical emergency until proven otherwise, even if the pain subsides.

26. Stroke-related headache

Strokes occur when blood supply to the brain is interrupted. While the most recognised stroke symptoms are facial drooping, arm weakness, and speech difficulty (think FAST: Face, Arms, Speech, Time), severe sudden headache is also a key symptom, particularly in haemorrhagic strokes where a blood vessel bursts.

What to do: call 999 immediately. Time is critical with strokes. Every minute of delayed treatment increases the risk of permanent damage.