Quick Answer
If you’re wondering what causes nausea and headache together, the most common answers are dehydration, migraine, hangover, viral illness (flu, gastroenteritis, COVID), tension or stress headache, low blood sugar, motion sickness, perimenopause and pregnancy hormonal shifts, medication side effects, and overuse of pain relievers themselves. Less common but more urgent causes include high blood pressure crisis, concussion, and meningitis. Sudden severe headache with nausea — the “worst headache of your life” — needs emergency evaluation. Book a Myers’ Cocktail or hydration IV or call (443) 563-1059.
Medically Reviewed by Dr. Brijen L. Joshi, MD · Medical Director, Vita Nova Ketamine & Wellness Clinic · Updated · 8 min read
Asking what causes nausea and headache at the same time is the right question — when those two symptoms travel together, your body is usually pointing to a smaller list of culprits than headache or nausea alone. This guide walks through the 12 most common causes, the warning signs that mean it’s time for emergency evaluation, and which causes respond well to IV hydration and Myers’ cocktail therapy at our Canton, Baltimore clinic.
In This Guide on What Causes Nausea and Headache
- When to Seek Emergency Care
- 12 Common Causes
- 1. Dehydration
- 2. Migraine
- 3. Hangover
- 4. Viral Illness
- 5. Tension Headache
- 6. Low Blood Sugar
- 7. Motion Sickness
- 8. Hormonal Shifts
- 9. Medication Side Effects
- 10. Caffeine Withdrawal
- 11. Hypertensive Episode
- 12. Concussion or Head Injury
- When IV Therapy Helps
- FAQ
When to Seek Emergency Care First
Before walking through what causes nausea and headache in everyday situations, know the red flags that mean go to the ER, not Google. CDC HEADS UP guidance and the NIH National Institute of Neurological Disorders and Stroke headache page highlight these warning signs:
- Sudden severe headache (“worst of your life,” “thunderclap”)
- Headache with stiff neck, fever, and confusion (possible meningitis)
- Headache after a head injury, with vomiting, drowsiness, or memory loss (possible concussion or bleed)
- Headache with weakness, numbness, slurred speech, or vision loss (possible stroke)
- Severe headache during pregnancy with vision changes or upper abdominal pain (possible preeclampsia)
- Persistent vomiting that prevents oral intake for more than 12 hours
12 Common Causes — What Causes Nausea and Headache Together
Once you’ve ruled out emergencies, the question of what causes nausea and headache simultaneously narrows to a manageable list. Most fall into one of these categories.
1. Dehydration
Dehydration is one of the most common answers to what causes nausea and headache in adults — and one of the easiest to fix. Cleveland Clinic’s overview of dehydration lists headache, dizziness, dry mouth, and nausea among hallmark mild-to-moderate symptoms. The fix: oral rehydration solution (Pedialyte, DripDrop, or homemade WHO recipe) over 1–2 hours, or IV hydration if oral intake isn’t enough.
2. Migraine
Nausea is a defining feature of migraine — present in roughly 70–90% of attacks. Mayo Clinic’s migraine overview describes the prodromal, aura, attack, and postdrome phases, and notes that gut-related symptoms are part of the neurology, not a separate problem. Migraine treatment ranges from over-the-counter NSAIDs and triptans to IV magnesium for severe attacks.
3. Hangover
A hangover is essentially a mix of dehydration, electrolyte depletion, B-vitamin depletion, and mild inflammation. That combination is exactly what causes nausea and headache the morning after. IV hydration with anti-nausea support resolves most hangovers in under an hour. See Hangover Detox IV →
4. Viral Illness
Influenza, gastroenteritis, COVID-19, and other viral infections frequently combine fever, headache, and nausea. CDC flu symptoms page lists this triad along with body aches and fatigue. The fix is usually time, fluids, and symptomatic care.
5. Tension Headache
Severe tension-type headaches can produce mild nausea, particularly when paired with poor sleep, screen fatigue, or jaw clenching. NIH PMC tension-type headache reference covers diagnostic criteria and management.
6. Low Blood Sugar (Hypoglycemia)
Skipping meals, intense exercise without fueling, and certain medications can drop blood glucose enough to cause headache, nausea, shakiness, and irritability. NIH NIDDK on hypoglycemia covers symptoms and the 15-15 rule for treatment.
7. Motion Sickness
When your inner ear and eyes disagree about motion, the result is the classic motion-sickness headache plus nausea — common during travel, on boats, or with VR/AR exposure. Johns Hopkins Medicine on motion sickness covers prevention strategies. Antihistamines (meclizine, dimenhydrinate) and acupressure bands help.
8. Hormonal Shifts
Menstrual migraines, perimenopause, and pregnancy are well-documented contributors to recurrent nausea and headache. NIH MedlinePlus on the menstrual cycle describes the hormonal swings that drive cyclic symptoms. Pregnancy-related headache with vision changes or upper abdominal pain warrants immediate medical evaluation.
9. Medication Side Effects (Including Rebound)
Medications themselves are a major answer to what causes nausea and headache. Common culprits include opioid pain medications, certain antibiotics, hormonal contraceptives, and — paradoxically — pain medications taken too often. Medication-overuse headache (or “rebound headache”) is well-recognized; American Family Physician’s overview of medication-overuse headache covers diagnosis and the gradual withdrawal approach.
10. Caffeine Withdrawal
Habitual caffeine drinkers who skip a morning coffee, taper off, or have surgery scheduled often develop a throbbing headache plus mild nausea within 12–24 hours — another common answer to what causes nausea and headache for desk workers and shift workers. A review indexed in PubMed Central outlines the caffeine-withdrawal syndrome. The fix is gradual taper rather than abrupt cessation when possible.
11. Hypertensive Episode
Most hypertension is silent, but acute spikes (systolic above 180 or diastolic above 120) can cause headache, nausea, blurred vision, and chest discomfort. NIH NHLBI high-blood-pressure resources describe hypertensive urgency. Severe headache with very high readings warrants ER evaluation.
12. Concussion or Head Injury
After any head impact, persistent or worsening headache with nausea, vomiting, or confusion is concerning for concussion or intracranial bleeding. CDC HEADS UP guidance is the standard for return-to-activity decisions.
When IV Therapy Helps With What Causes Nausea and Headache
Of the 12 conditions above, several respond particularly well to medical IV therapy in an outpatient setting:
- Dehydration — A liter of balanced electrolyte solution restores intravascular volume in 30 minutes. Hydration Boost IV →
- Migraine attacks — IV magnesium and B-complex (often combined with anti-nausea support) are commonly used for moderate-to-severe attacks not responsive to oral medication.
- Hangovers — IV hydration plus B-complex and anti-nausea medication resolves most hangovers in under an hour.
- Post-illness recovery — Patients recovering from gastroenteritis or flu often benefit from a Myers’ cocktail (B-complex, vitamin C, magnesium, calcium) once they can tolerate sitting up.
The Myers’ Cocktail IV was developed in Baltimore by Dr. John A. Myers in the 1950s and has been a staple of integrative medicine for understanding what causes nausea and headache that responds well to combined nutrient IV therapy.
Save with Membership
Vitality Circle — $99.99/month
Patients who deal with recurrent migraine, hangover-prone weekends, or chronic dehydration get the most value from Vitality Circle, especially when figuring out what causes nausea and headache for their specific pattern. Members receive:
- One free standard IV every month — Hydration, Myers’, or any standard formula
- 25% off premium treatments, including NAD+ IV therapy
- 25% off all add-on boosters and IM shots
- Priority booking for same-day relief during a migraine or post-event
Note: NAD+ is a premium treatment and is never included in the free monthly benefit; members receive 25% off NAD+ instead.
Frequently Asked Questions
What causes nausea and headache that lasts for days?
Persistent symptoms over multiple days suggest viral illness, prolonged migraine status (status migrainosus), medication-overuse headache, or — less commonly — a more serious condition warranting evaluation by a primary care provider or neurologist.
Can dehydration alone cause nausea and headache?
Yes. Mild-to-moderate dehydration commonly produces both symptoms together, especially after exercise, alcohol, illness, or during summer heat. Oral rehydration solution typically resolves it within 1–2 hours; IV hydration in 30–60 minutes when oral isn’t enough.
When does nausea and headache mean something serious?
Sudden severe (“thunderclap”) headache, headache with neurological signs (weakness, numbness, slurred speech), headache after head injury, headache with stiff neck and fever, and severe headache in pregnancy all warrant emergency evaluation.
Does Myers’ cocktail help with what causes nausea and headache?
A Myers’ cocktail can help when the underlying cause is dehydration, B-vitamin or magnesium depletion, or mixed post-illness recovery. It’s not a substitute for migraine-specific medications when migraine is the primary diagnosis. We assess fit during a brief consultation.
How much does an IV cost for nausea and headache relief?
Hydration Boost IV starts at $149; Myers’ Cocktail and Hangover Detox at $199. Vitality Circle members ($99.99/month) get one free standard IV every month, which makes ongoing use far more affordable for people with recurrent symptoms.
Can low blood sugar cause nausea and headache?
Yes. Skipped meals, prolonged fasting, intense exercise without fuel, and certain medications can produce hypoglycemia, which classically causes shakiness, sweating, headache, and nausea. The 15-15 rule (15 g of fast carbs, recheck in 15 minutes) is the standard correction.
Could pain medication itself be what causes nausea and headache?
Yes — medication-overuse headache (rebound headache) is a recognized syndrome where frequent use of pain relievers paradoxically maintains headache. If you’re taking acetaminophen, NSAIDs, or triptans more than 10–15 days per month, talk with your primary care provider.
Need Relief From Nausea and Headache Today?
If dehydration, hangover, migraine, or post-illness recovery is what causes nausea and headache for you, IV hydration or Myers’ cocktail can resolve symptoms in under an hour.
Medically Reviewed By
Dr. Brijen L. Joshi, MD
Medical Director, Vita Nova Ketamine & Wellness Clinic. Dr. Joshi oversees clinical protocols and patient safety standards for all IV vitamin therapy, NAD+ IV therapy, ketamine infusion, and SPRAVATO® treatments at our Canton, Baltimore clinic. Vita Nova is LegitScript-certified and REMS-compliant.
This article is for general informational purposes only and does not constitute medical advice. Sudden severe headache, neurological symptoms, headache after head injury, or persistent vomiting that prevents fluid intake all warrant emergency evaluation. Consult a licensed healthcare provider for personal guidance.
