7 Key Signs You’re Dehydrated and How to Stay Hydrated, According to Experts

You might believe you’re staying adequately hydrated, especially if you’re frequently sipping coffee throughout the day, but you might be more dehydrated than you realize. The human body is approximately 70% water, and daily activities can lead to a loss of up to two and a half liters. Even breathing contributes to fluid loss, with about half a liter exhaled daily.

How Much Water Should You Drink Each Day?

Maintaining fluid balance is essential, and drinking sufficient water plays a crucial role. According to the Mayo Clinic, which references data from the U.S. National Academies of Sciences, Engineering, and Medicine, adult women should consume around 11.5 cups or 2.7 liters of fluids daily, while men need about 15.5 cups or 3.7 liters. Although roughly 20% of this intake can come from food sources like fruits, soups, and vegetables, few individuals actually meet these recommended amounts.

Signs You May Be Dehydrated

To better understand if you’re dehydrated, we consulted Dr. Lela Ahlemann, a specialist in dermatology, proctology, and nutritional medicine. She highlighted seven common indicators that you might not be drinking enough water:

1. Dry Mouth and Thirst

A classic symptom of dehydration is feeling thirsty and experiencing a dry mouth. This sign suggests that your body is signaling a need for fluids. Dr. Ahlemann notes that a dry mouth not only indicates dehydration but can also impair your immune system. “A dry mouth can lead to a weakened oral mucosa, which serves as an immune defense, making you more susceptible to infections,” she explains. If you can’t drink water, at least rinse your mouth with some liquid.

2. Dark Urine or Reduced Urine Output

Dr. Ahlemann explains that concentrated urine, which appears darker, is a sign of insufficient hydration. Ideally, urine should be a pale yellow. “If your urine is dark, it’s a clear indication that you need to drink more water. Observing your urine color is a simple self-check to determine if you’re adequately hydrated.”

3. Headaches and Dizziness

Dehydration can reduce blood volume, which in turn affects the brain’s supply of blood and nutrients, leading to headaches and dizziness. “Headaches and dizziness are often caused by this decreased blood volume,” says Ahlemann. If you experience frequent dizziness, seeking medical advice is recommended.

4. Fatigue and Difficulty Concentrating

Lack of fluids can also result in fatigue and difficulty concentrating. This is because reduced blood volume impacts brain function. “Fatigue and trouble focusing are common signs of dehydration. The decreased blood volume means that the brain is not receiving optimal support,” explains Dr. Ahlemann.

5. Dry Skin and Lips

Dry skin and lips are additional indicators of dehydration. Dr. Ahlemann suggests a simple test to check for dehydration: “Pinch the skin on the back of your hand and pull it up. If the skin returns slowly to its original position, it indicates dehydration.” Dry skin can also cause itching and make your skin appear paler due to insufficient oxygen and micronutrient supply.

6. Dark Circles Under the Eyes

Not drinking enough water can make blood thicker, which may make blood vessels more visible, resulting in dark circles and sunken eyes. “If you’re not drinking enough, the blood can become thicker, making blood vessels more noticeable. This can lead to dark circles, sunken eyes, and increased wrinkles around the eyes,” says Ahlemann.

7. Constipation

Constipation is a common consequence of inadequate fluid intake. When you drink insufficient water, your intestines absorb too much water from stool, reducing its volume and leading to constipation. Dr. Ahlemann notes, “In medical terms, constipation is described as having hard stools due to dehydration. Many people are unaware that insufficient hydration can also cause bloating.”

Understanding these signs can help you recognize when your body needs more water and take appropriate steps to stay hydrated.