Headaches are generally classified as primary, without an underlying illness, or as secondary, caused by an underlying condition like dehydration, infection, injury, vascular disease, or tumour, which needs urgent medical evaluation and management.
Primary headaches like migraine, tension-type, and cluster headaches are usually benign, though disabling, and can be avoided through lifestyle changes, managed with standard treatments, or may need medical evaluation if they do not respond and persist.

LOCATION OF COMMON HEADACHES

Location is a good clue to the cause of a headache.
• Entire Head/Tight Band: Often a tension headache caused by stress, fatigue, or muscle strain.
• One Side (Temple/Forehead): Typically, a migraine, which may be accompanied by nausea, throbbing pain, and sensitivity to light or sound.
• Forehead and Front Part of Head: Indicates sinus (vacuum) headache or tension-type headaches.
• Back of the Head/Neck: Usually a headache stemming from neck issues (cervicogenic), or a tension headache.
• Behind the Eye/Eye Area: Sinus (dull ache) or a cluster headache (intense, sharp pain).
• Both sides: In a high blood pressure crisis.

THE AVOIDABLE

Many headaches are considered "avoidable" because they are triggered by specific lifestyle factors or environmental exposures. Identifying and eliminating these triggers can significantly reduce the frequency of attacks.
• Dietary Triggers: Common culprits include alcohol (especially red wine), caffeine (or withdrawal from it), and foods containing nitrates (processed meats) or MSG. Skipping meals or fasting can also trigger pain due to blood sugar fluctuations.
• Physical & Environmental Factors: Dehydration, poor posture (slouching at a desk), and eye strain due to reading in poor light are frequent, avoidable causes. Environmental triggers like strong odours, bright lights, and loud noises should also be minimized.
• Stress Management: Stress is a major driver of tension headaches. Techniques such as yoga, meditation, and regular exercise can help reduce physical tension.
• Lifestyle Factors: Eye strain due to excessive screen time, lack of sleep, or irregular sleep patterns, skipped meals, poor posture, and excessive caffeine and alcohol consumption.

THE MANAGEABLE

Common primary headaches can often be managed through over-the-counter (OTC) or prescription medications and self-care.
• Tension-Type Headaches: The most common type, often felt as a tight band or steady ache around the head. It is commonly caused by stress, poor posture, or muscle strain. It usually responds well to OTC pain relievers like aspirin, ibuprofen, or paracetamol.
• Migraines: Intense, throbbing pain often on one side, frequently accompanied by nausea, vomiting, and sensitivity to light or sound. Management includes triptans (available as pills, nasal sprays, or injections) for acute attacks and preventive medications like beta-blockers or antidepressants for frequent sufferers.
• Cluster Headaches: Excruciating, piercing pain behind or around one eye, often happening in cycles. These are treated with oxygen therapy or specialized prescription medications.
• Sinus or vacuum Headaches: Deep, constant pain in the forehead or cheekbones, usually accompanied by sinus symptoms like a runny nose. It is rapidly relieved by an oxymetazoline nasal decongestant spray.
• Hormonal Changes: Common in women during menstruation, pregnancy, or menopause.
• Self-Care for management: Resting in a dark, quiet room, using hot or cold compresses, gentle neck stretching, ensuring proper hydration, and taking over-the-counter medication can provide relief for many manageable headaches.

THE CONCERNING

Secondary headaches are often symptoms of serious, potentially life-threatening conditions, needing immediate or early medical attention.
• A thunderclap headache is a sudden, excruciating headache peaking within 60 seconds. It can indicate a brain bleed or aneurysm that can cause sudden death and needs an immediate hospital visit.
• Acute angle-closure glaucoma is a medical emergency involving rapidly increased pressure in the eye, causing severe headaches, intense eye pain, blurred vision, and nausea.
• Neurological warning signs accompanying a headache, like confusion, weakness, numbness, problems with speech or hearing, vision changes or loss, memory loss, seizures, or loss of consciousness, can be signs of a stroke, encephalitis, or brain tumour.
• Fever, headache, aches in muscles or joints, fatigue, or weakness may be a flu-like presentation of encephalitis.
• Fever, headache with a stiff neck, nausea or vomiting, or rash may signal meningitis or encephalitis.
• Weight loss with headache may be due to immunosuppression or debilitating diseases like tuberculosis, cancer, and HIV.
• High blood pressure (hypertension) is called the "silent killer" because it usually causes no symptoms, even at dangerous levels, until it has caused damage. When symptoms do occur, often in a hypertensive crisis, it is a throbbing, pulsating pain affecting both sides of the head and worsening with activity, and can include nausea or vomiting, shortness of breath, dizziness, chest pain, palpitations, nosebleeds, and vision changes.
• Postural (orthostatic) headaches are worse when upright, better when lying down, and exertion headaches are triggered by physical activity. These headaches are usually benign but may indicate underlying issues such as cerebrospinal fluid (CSF) leaks, head injury, neck issues, or vascular changes needing medical attention.
• Post-Traumatic Headache (PTH) can be constant or intermittent, and commonly occurs after a concussion or minor blow or hit to the head, whiplash, or fall. These headaches typically begin within seven days of the incident and often feel like tension headaches or migraines. They may also be due to slow intermittent venous bleeding in the brain, requiring medical evaluation and management.
• A headache from coughing (or straining, laughing, sneezing) is a sudden, sharp pain that usually lasts from a few seconds to 30 minutes, often caused by increased pressure in the chest and head. While most are benign primary headaches, some are secondary to underlying conditions (e.g., Chiari malformation, tumours in the brain) and require prompt medical evaluation, especially if new, severe, or persistent.
• Eye strain, usually due to extended digital device use or poor lighting or reading for extended periods, uncorrected refractive errors, and dry eyes, can cause dull, aching pain behind the eyes, and sensitivity to light, tired, burning, itching eyes, along with blurred/double vision and pain in the neck, shoulders, or back.
• Ear-related headaches or pain radiating to the head, with pressure or sharp, stabbing sensations behind the ears, often stem from inflammation, infections (otitis media), eustachian tube (connecting the ear to the nose) blockages, occipital neuralgia, or compacted earwax.
• Dental problems are a common cause of dull, persistent headaches around the temples, forehead, or behind the eyes, often resulting from infections/abscesses, impacted teeth, or teeth grinding (bruxism), muscle tension, jaw misalignment, and Temporomandibular Joint (TMJ) disorders of the lower jaw.
• Occipital neuralgia is a distinct headache disorder characterized by intense, sharp, stabbing, or shock-like pain in the upper neck, back of the head, or behind the ears caused by inflamed or injured nerves. It is treated with heat, massage, anti-inflammatory medications, nerve blocks, or sometimes surgery.
• Medication Overuse Headache: Ironically, using pain relief too frequently (more than 2-3 times a week) can cause "rebound" headaches that make the condition worse over time.
• New Patterns: A new type of headache, especially after age 50, or headaches that wake you from sleep, or a headache that progressively worsens over several weeks, should be professionally evaluated.
• Headaches are common during pregnancy, especially in the first and third trimesters, often triggered by hormonal shifts, fatigue, dehydration, stress, or caffeine withdrawal. While typically harmless early on, severe or persistent headaches, especially in the third trimester, can indicate conditions like preeclampsia and require immediate medical evaluation.
• In infants and children, unusual irritability or high-pitched crying may indicate a secondary headache and may be accompanied by a soft spot on the head (bulging fontanelle), poor feeding or refusing to wake for feedings, or body stiffness.
Seek emergency medical care if you or someone else experiences sudden, severe headache, confusion, disorientation, hallucinations, seizures, or loss of consciousness. Sudden severe headache with intense eye pain, drastic vision changes (blind spots, flashes of light, severe blurriness, double vision, halos around lights), vomiting, fever, or red eyes, needs emergency eye evaluation and treatment.

DIAGNOSTIC TESTS

• CT Scan to detect bleeding, swelling, or structural problems like brain tumours.
• MRI to check for vascular issues, multiple sclerosis, or brain abnormalities.
• Blood tests - CBC to check for infection or anaemia, thyroid profile, and vitamin B12 and D levels.
• Lumbar Puncture (Spinal Tap) to diagnose meningitis or infections in the central nervous system.
• Eye Examination to rule out glaucoma or vision-related strain. Also, ENT and dental check.
• EEG is performed if the patient experiences seizures or loss of consciousness.
PREVENTION AND SELF-CARE
• Identify Triggers: Keep a headache diary to track patterns related to food, stress, or environmental factors like bright lights.
• Healthy Routine: Maintain a regular sleep schedule (7-9 hours), eat balanced meals at consistent times, and stay well-hydrated.
• Stress Management: Practice relaxation techniques such as yoga, meditation, or deep breathing.
• Ergonomics: Maintain good posture, especially during long screen use, and follow the 20-20-20 rule (look 20 feet away every 20 minutes for 20 seconds).
• Dietary Adjustments: Limit alcohol and caffeine, and avoid processed meats containing nitrates, MSG, and other personal triggers.
Dr. P.S. Venkatesh Rao is a Consultant Surgeon, Former Faculty CMC (Vellore), AIIMS (New Delhi), and a polymath in Bengaluru, drpsvrao.com