From the Guidelines
Dehydration can cause headaches.
Dehydration and Headaches
- Dehydration is known to cause a range of symptoms, including headaches, due to the reduction in fluid volume and electrolyte imbalance in the body.
- Although the provided evidence does not directly address the relationship between dehydration and headaches, it highlights the various consequences of dehydration, such as reduced cognitive function, orthostatic hypotension, and increased risk of acute confusional state 1.
- The development of hyperthermia during exercise in hot ambient conditions can lead to progressive dehydration, resulting in a hypohydrated state characterized by a decrease in plasma volume and an increase in plasma osmolality 1.
- Dehydration can also lead to more severe complications, such as thrombosis, orthostatic hypotension, syncope, falls, injuries, and bone fractures, especially in individuals with pre-existing medical conditions 1.
- While the evidence focuses on the management of dehydration in various contexts, including exercise-induced dehydration and dehydration in patients with diabetes, it emphasizes the importance of proper hydration to prevent dehydration-related complications 1.
- In general, dehydration can cause a range of symptoms, including headaches, due to the disruption of normal bodily functions, and it is essential to assess dehydration and fluid deficit through careful physical examination, especially in vulnerable populations 1.
From the Research
Dehydration and Headaches
- Dehydration can cause headaches, as evidenced by studies that show a relationship between fluid balance and headache disorders 2, 3, 4, 5.
- Research suggests that dehydration alone may cause headache, but it often exacerbates underlying medical conditions such as primary headache disorders or other conditions dependent on fluid balance 2.
- Increasing daily water intake has been shown to reduce the frequency and severity of headaches in some studies 3, 5.
- A study found that approximately 1 in 10 subjects experienced water-deprivation headache, which was relieved by drinking water within 30 minutes to 3 hours 4.
Mechanisms and Associations
- The exact mechanism of dehydration-induced headache is not fully understood, but it is thought to involve changes in serum osmolality and the meninges 4.
- Dehydration has been linked to various types of headaches, including migraine, tension-type headache, and post-lumbar puncture headache 2, 3, 5.
- Some studies have found a significant negative correlation between daily water intake and migraine headache characteristics, suggesting that increased water intake may help reduce headache severity 5.
Contrasting Findings
- Not all studies have found a significant association between dehydration and headache, with one study concluding that dehydration is an unlikely cause of headache during a single day of fasting 6.
- The relationship between dehydration and headache is complex and may depend on various factors, including individual differences in fluid balance and headache disorders 2, 6.