Dehydration, though seemingly simple, can have profound health consequences, especially when stemming from underlying diseases. For adults, understanding the diseases that cause dehydration can pave the way for better preventive measures and optimized health outcomes.


Water makes up approximately 60% of the human body. It plays a crucial role in a range of physiological processes, from temperature regulation to digestion. Hence, the equilibrium of fluid levels is paramount. But certain diseases can disturb this balance, leading to dehydration in adults.

1. Diabetes

A condition characterized by high blood sugar levels.

  • Mechanism: Excess sugar in the bloodstream pulls water out of cells, causing increased urination to remove the sugar, leading to dehydration.
  • Signs: Frequent thirst and urination, dry mouth, and fatigue.

2. Kidney Diseases

The kidneys regulate fluid balance, but when they’re compromised, problems arise.

  • Mechanism: Impaired kidney function can reduce urine production and fluid excretion, causing fluid retention initially and later dehydration.
  • Signs: Swollen ankles, feet, or hands and shortness of breath.

3. Gastrointestinal Illnesses

Diseases affecting the stomach and intestines.

  • Mechanism: Conditions like gastroenteritis cause vomiting and diarrhea, leading to a rapid loss of fluids and salts.
  • Signs: Severe thirst, dark yellow urine, and dizziness.

4. Addison’s Disease

A disorder where the adrenal glands don’t produce enough hormones.

  • Mechanism: Reduced aldosterone production affects kidney function, leading to the excessive excretion of salt and subsequently water.
  • Signs: Craving for salt, severe fatigue, and low blood pressure.

5. Cystic Fibrosis

A genetic disorder affecting mainly the lungs but also the pancreas, liver, kidneys, and intestine.

  • Mechanism: Thick and sticky mucus can block the tubes and ducts in the body, including those in the sweat glands, causing excessive salt loss during sweating.
  • Signs: Salty-tasting skin, persistent coughing, and respiratory infections.

FAQ Section

  • Q: Are there any preventive measures for dehydration?

    • A: Yes. Regular hydration, monitoring fluid loss especially during illnesses, and early diagnosis and management of underlying diseases can prevent dehydration.
  • Q: Can medications cause dehydration?

    • A: Some medications, like diuretics or those for blood pressure, can increase urination, potentially leading to dehydration.
  • Q: How is dehydration treated?

    • A: Mild cases can be managed with increased fluid intake, while severe cases may require hospitalization and intravenous fluids.


Recognizing the diseases that cause dehydration in adults is not just about managing thirst—it’s about understanding the intricate balance our body maintains and the diseases that disrupt it. With knowledge comes empowerment, and with empowerment comes better health.