Dehydration Headache
We have all been there. An extra glass of wine, or that extra beer during the Superbowl weekend. That hot summer evening when you push yourself to do that extra mile. Or that time you had that bad flu.
Dehydration is a universal phenomenon. And it happens to most of us, every day. Trying to keep up with fluids sometimes is a challenging task. Some of us do better than others in staying well-hydrated. But did you know that dehydration can present itself as a headache? It is surprisingly more common than previously thought.
What is dehydration?
By definition, dehydration is loss of fluid from the body. 70% of our body is water. This water circulates within the blood vessels, some inside our cells and some water exists in the space between our cells. Nutrients and minerals circulate within the cells of our body through this water. When you get dehydrated, water and electrolytes are lost. This is what leads to symptoms.
When is headache a symptom of dehydration?
In many individuals, symptoms can develop even with mild dehydration. These symptoms include fatigue and lightheadedness. At times, dehydration can reduce blood pressure which can cause dizziness and nausea.
In younger individuals, mild-moderate dehydration presents mainly with headaches. This is typical with alcohol withdrawal or hiking at a higher altitude. When our body gets dehydrated, certain hormones are released that conserve salt and water through our kidneys. One such hormone is vasopressin and a higher level of this in our plasma may be responsible for the dehydration headache.
Diagnosis of dehydration headaches can be challenging at times when the situation is less obvious. In a cooler environment, an individual can get dehydrated and not know about it. This is typical in those who do not have a habit of drinking enough water during the day. The “caffeine culture” is likely to be blamed for it.
Air-conditioned offices and frequent coffee ingestion can suppress your drive to drink enough water. And younger individuals have a tendency to drink sodas instead of water during the day to get that caffeine boost. The result? A dehydration headache right in the middle of a meeting during the afternoon.
Dehydration headaches typically have some distinctive signs. They usually are not associated with any visual changes or an aura (a warning sign such as nausea) that is typical of migraines. Dehydration headaches are also not focal or restricted to one area- e.g. on the side of the head or the back. They tend to be more frontal, or along the forehead and diffuse. And as expected, they improve with hydration.
What are the signs of dehydration?
Identifying dehydration as a cause of headaches has its advantages. It is quickly treatable with fluids. That may be using just water to begin with or with an electrolyte drink that is rich in sodium, potassium and magnesium, such as MAGNAK®. Electrolytes have advantages when used for rehydration- sodium and potassium allow delivery of electrolytes and water to the cells within the body while magnesium can cause relaxation of the endothelial cells which are specialized cells lining the blood vessels. This prevents blood vessels from staying contracted too long, which is the leading cause of headaches in this case.
Clinical signs of dehydration can be obvious. A dry tongue is a classic sign of dehydration. When the body loses enough water, mucous membranes in the mouth cannot stay hydrated. Oral secretions can drop leading to a dry “parched” tongue.
Another easy method to assess hydration status of an individual is by looking at skin turgor. In this method, the skin around the forearm or the thigh is pinched and assessed for retraction. In a well-hydrated state, the skin is elastic and retracts quickly. In moderate to severe dehydration, the skin takes much longer to retract- this is called a decrease in skin turgor. This degree of dehydration usually requires hospitalization and aggressive intravenous hydration under the care of medical professionals.
How to treat dehydration headaches?
Luckily, this part is simple. Dehydration is treated by hydrating the body- but not just with water. Ideally, the rehydration beverage should contain water as the base, but also some electrolytes. This is because a loss of water is almost always accompanied by a loss of electrolytes dissolved in our body water. Hence, replacement of water deficit by hydration but not that of electrolytes, particularly of sodium, can lead to hyponatremia in some individuals. This condition, characterized by a low blood sodium level can be dangerous and lead to a persistent headache.
Hence, an electrolyte mix dissolved in water, such as MAGNAK®, can help significantly with dehydration headaches. By effectively replacing fluid and electrolyte deficit, magnesium has significant advantages of acting directly on blood vessels preventing a prolonged vasoconstriction caused by vasopressin. Magnesium sulfate and saline have been the backbone of treating severe headache for decades in an in-patient setting.
The take home message
Dehydration can often present as headaches. And it does not have to be a hot or a humid day to get dehydrated. When a sudden headache strikes after a long day of work, individuals need to think about their total fluid intake during that day.
Staying well hydrated can help prevent dehydration headaches. If they do strike, an electrolyte mix such as MAGNAK® can be a quick fix. This is a much better alternative than that usual shot of espresso. Caffeine does not help with dehydration headaches, hydration does!
By: Sourabh Kharait, MD, PhD-Founder/CEO.
Dr. Kharait is an MD and a practicing Nephrologist in Northern California. He completed his Residency in Internal Medicine and Fellowship in Nephrology from the University of California, San Francisco. He has a PhD in Molecular Physiology from the University of Pittsburgh and specializes in treating patients with electrolyte disorders and kidney diseases.
