Dehydration Headache : Symptoms, Treatment, & Prevention 2024

Headaches can be caused by many factors like stress, lack of sleep, food sensitivities, and even changes in the weather. However, one of the most common causes of headaches that is often overlooked is dehydration.

What Is Dehydration Headache?

A dehydration headache is exactly what it sounds like – a headache caused by not drinking enough water. When your body doesn’t have enough fluid, it leads to an imbalance of electrolytes like sodium and potassium. This causes the blood vessels in your head to constrict, which then causes pain and discomfort.

Some common symptoms of dehydration headache include:

  • Dull, throbbing pain on both sides of the head
  • Pain behind the eyes
  • Dry mouth
  • Increased thirst
  • Dizziness
  • Irritability
  • Fatigue
  • Loss of concentration
  • Constipation

While mild dehydration may only cause a minor headache, severe dehydration can result in a migraine-like headache that can be debilitating.

What Causes Dehydration Headaches?

There are a few key reasons why you may become dehydrated and experience headaches:

Inadequate Fluid Intake

The most obvious cause is not drinking enough water during the day. The recommended daily intake of water is around 8 glasses for women and 12 glasses for men. If you consume less than this, you put yourself at risk of dehydration.

Certain factors like hot weather, intense exercise, and illnesses like fever and diarrhea can increase your fluid requirements even more. Not increasing your water intake to account for these can leave you dehydrated.

Excessive Caffeine and Alcohol

Beverages like coffee, tea, soda, and energy drinks act as diuretics, meaning they make you urinate more frequently. This leads to the loss of fluids and electrolytes from your body.

Alcohol is another diuretic that can cause dehydration. After a night of drinking, you may wake up with a headache from a loss of fluids.

Some Medications

Certain medications like diuretics, blood pressure drugs, and some antihistamines have dehydrating effects on the body. Read the label or check with your pharmacist to know if any medicines you take can lead to dehydration.

Low Dietary Mineral Intake

Having low levels of minerals like potassium, calcium, and magnesium in your diet also increases the risk of headaches. These help maintain fluid balance in the body, so a deficiency makes you prone to dehydration.

Tips to Prevent Dehydration Headaches

Making sure you drink plenty of fluids and consume mineral-rich foods is key to preventing dehydration headaches. Here are some useful ways to stay hydrated:

  • Carry a water bottle – Having water readily available will remind you to sip it throughout the day. Aim for the recommended daily intake.
  • Drink before you’re thirsty – Don’t rely on thirst as your cue to drink water. By the time you’re thirsty, you’re likely already dehydrated. Get into the habit of drinking water with meals and taking sips between.
  • Avoid excessive caffeine and alcohol – Limit caffeine to 1-2 cups of coffee per day and avoid more than 1 alcoholic drink per day. Both act as diuretics.
  • Eat water-rich fruits and veggies – Foods like cucumbers, watermelon, lettuce, celery, and berries help meet your fluid needs.
  • Adjust your water intake – Drink more water on hot days, when exercising, and when sick. These conditions deplete your body’s water levels.
  • Don’t wait for headaches – Prevent them by making sure you’re adequately hydrated daily, not just when already feeling symptoms.
  • Take electrolytes – Drinks like coconut water and sports drinks replenish electrolytes like potassium that get depleted with dehydration.

Keeping well-hydrated may seem simple but requires some diligence. Forming habits like having a water bottle and setting reminders to drink water will reduce your risk of dehydration.

Dehydration Headache Symptoms

Dehydration headaches can range from mild to severe depending on the extent of your dehydration. Here are some of the most common symptoms:

Mild Dehydration

In the early stages of dehydration, you may experience:

  • Slight headache
  • Dry mouth and increased thirst
  • Fatigue
  • Dizziness when standing up suddenly

Moderate Dehydration

As dehydration worsens, symptoms also progress:

  • Headache localized to the front and back of the head
  • Nausea
  • Muscle cramps
  • Irritability
  • Sleepiness
  • Decreased urine output

Severe Dehydration

Without treatment, severe dehydration can result in:

  • Throbbing headache on both sides of the head
  • Rapid heartbeat
  • Fainting
  • Lack of sweating even during the heat
  • Little to no urination
  • Fever
  • Confusion
  • Slurred speech
  • Seizures

Severe dehydration constitutes a medical emergency. Prompt treatment with intravenous fluids is needed to restore fluid balance.

When to See a Doctor

You should seek medical care if you experience any of the following:

  • Headache after minimal activity like walking
  • Headache that gets worse despite hydration efforts
  • Headache accompanied by fever, neck stiffness, nausea, and vomiting
  • Severe headache that doesn’t improve after taking over-the-counter pain medication
  • Headache in pregnant women and small children
  • Persistent or recurrent dehydration headaches

Seeking timely treatment can avoid complications like electrolyte imbalances and prevent the headache from worsening. Doctors can provide IV fluids and medications to relieve headache symptoms.

Diagnosing Dehydration Headaches

To check for dehydration headaches, doctors will:

  • Take your history – They will ask about your fluid intake, any contributing factors like exercise, medications you take, other symptoms like nausea and fatigue, and how much water you need to drink to feel better.
  • Conduct a physical exam – They will check your vital signs like temperature, heart rate, blood pressure, and oxygen levels. Signs of dehydration include increased heart rate, low blood pressure, and lack of sweat.
  • Order tests – If needed, they may order blood tests to check electrolyte levels, kidney function, and signs of dehydration. Low blood sodium is a common finding.
  • Consider other causes – Your doctor will also evaluate your symptoms to rule out other causes like migraine, tension headache, sinus infection, or medication overuse headache.
  • Assess severity – Based on your symptoms and test results, your doctor can determine whether you have mild, moderate, or severe dehydration and recommend appropriate treatment.

Home Remedies for Dehydration Headaches

If you have mild to moderate dehydration, you can use these remedies to help recover at home:

  • Drink water – Sipping small amounts of water gradually is key. This gives your body time to excrete excess fluid without triggering nausea. Drink electrolyte-containing drinks as tolerated.
  • Rest – Take it easy and avoid strenuous activities that worsen headaches and dehydration.
  • Pain medication – Over-the-counter NSAIDs like ibuprofen, naproxen, or aspirin can relieve headache pain. Acetaminophen is another option.
  • Caffeine – A little caffeine from tea, coffee, or soda can help constrict blood vessels and relieve pain temporarily.
  • Cool compress – Applying an ice pack or cold cloth to your forehead and temples can soothe headaches.
  • Peppermint essential oil – Its cooling effect can relieve headache pain and nausea associated with dehydration.
  • Acupressure – Applying pressure to points on your hands and feet associated with headache and nausea can provide relief.

Make sure you continue sipping water and electrolyte drinks regularly even after you feel better to restore your fluid levels.

Medical Treatment for Dehydration Headaches

If your dehydration is moderate-severe or not improving with home care, seek prompt medical treatment. Options may include:

  • IV fluids – Intravenous fluids are used to restore fluid volume and electrolyte balance. Saline solutions and IV electrolytes rapidly hydrate the body and treat dehydration.
  • Medications – Metoclopramide helps with nausea and vomiting while IV painkillers like ketorolac provide headache relief.
  • Hospitalization – If vomiting and diarrhea persist, preventing oral rehydration, hospital admission allows hydration and medication administration through IV under monitoring.
  • Address underlying causes – Your doctor will treat related conditions like diarrhea or replace medications contributing to dehydration.
  • Prevent recurrence – They will guide daily water intake, signs of dehydration to watch for, and when to follow up.

Early medical care for dehydration can help resolve headaches faster and prevent hospitalization in severe cases.

How to Prevent Dehydration Headaches

Staying well hydrated every day is the best way to avoid dehydration headaches. Here are some tips:

  • Drink at least 8 glasses of water daily. Carry a water bottle as a reminder.
  • Increase water intake with exercise, heat exposure, fever, or illness.
  • Eat water-rich fruits and vegetables to boost hydration.
  • Limit caffeine and alcohol which act as diuretics.
  • Drink coconut water or sports drinks to replenish electrolytes.
  • Don’t wait until thirsty to drink as that indicates dehydration.
  • Check urine color. Pale yellow means you’re well-hydrated.
  • Monitor for early signs of dehydration like headache, fatigue, and dizziness.
  • Keep hydrated by drinking water regularly throughout the day.
  • Carry electrolyte tablets or powders when traveling or hiking to quickly replenish fluids.
  • Check with your doctor if certain medications you take may cause dehydration.

With some diligence, you can make sure you stay well hydrated and avoid the annoyance of those dehydration headaches!

Dehydration Headache FAQs

Is dehydration the most common cause of headaches?

Dehydration is one of the most common causes of headaches. It accounts for around 5% of all headaches. While not the single most prevalent cause, it is easily avoidable through adequate daily fluid intake.

Should I go to the ER for a dehydration headache?

Most dehydration headaches can be managed at home by gradually rehydrating with water and electrolyte drinks. Seek emergency care only if you have symptoms like fainting, seizures, fever, neck stiffness, or no urine output that indicates severe dehydration.

How much water should you drink to treat dehydration headaches?

There’s no set amount of water to relieve a dehydration headache but aim to drink around 16 ounces every hour. Sip slowly rather than gulping down a large amount at once. Drink until urine is a pale clear color indicating you are well hydrated.

How long does a headache last with dehydration?

If treated properly, a dehydration headache can resolve within a few hours to 1-2 days at most. Drink water and electrolyte beverages regularly during this time. Seek medical advice if the headache persists beyond 2 days despite hydration efforts.

Can dehydration cause a headache for days?

Dehydration headaches shouldn’t persist for days if you are drinking adequate fluids and replacing electrolytes. Prolonged headaches for 3 or more days could indicate another underlying medical condition requiring evaluation. See your doctor if the headache isn’t relieved by self-care measures.


Dehydration is one of the most preventable causes of headache. By making sure you consume sufficient water and electrolytes daily, you can avoid becoming dehydrated and head off headaches before they start. Know the early signs of dehydration like fatigue and dizziness and start drinking water at the very first hint of symptoms.

Keep water handy and make hydration a habit. If you already have a dehydration headache, resolve it safely with gradual rehydration using water, electrolyte drinks, and home remedies. Seek prompt medical attention for any signs of severe dehydration. With adequate fluid intake and prompt treatment when needed, you can stay headache-free.

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