It’s normal to feel thirsty after eating spicy foods or performing strenuous
exercise, especially when it’s hot. But sometimes your thirst is stronger than
usual and continues after you drink. You may even experience blurred vision and
fatigue. These are symptoms of excessive thirst, which may signal a serious
underlying medical condition.
Causes of excessive
Causes may include:
- eating salty or spicy foods
- strenuous exercise
- significant loss of blood
- certain prescription medications, including
lithium, diuretics, and certain antipsychotics
Frequent excessive thirst or thirst that can’t be quenched can be symptoms
of serious medical conditions, such as:
occurs when you lack the proper amount of fluids for your body to function
properly. Severe dehydration is life-threatening, especially for infants
and young children. Dehydration can be caused by illness, profuse
sweating, too much urine output, vomiting, or diarrhea.
- Diabetes mellitus: Excessive thirst can be caused by high blood sugar
(hyperglycemia). It’s often one of the first noticeable symptoms of this
type of diabetes.
- Diabetes insipidus: This form of diabetes occurs when your body can’t
regulate fluids properly. This causes an imbalance of water in your body,
leading to excessive urination and thirst.
- Dipsogenic diabetes insipidus: This condition is caused by a defect in the thirst
mechanism, resulting in increased thirst and liquid intake.
- Heart, liver, or kidney failure
This is a dangerous illness caused by a severe inflammatory reaction from
infection with bacteria or other germs.
When to seek
Thirst is your body’s way of telling you that it’s low on fluids. In normal
circumstances, you should be able to quench your thirst fairly quickly.
However, if your urge to drink remains constant, or does not go away after you
drink, it may be a sign of a serious health problem, especially if combined
with other symptoms. This constant urge to drink could also be a psychological
You should consult with your doctor if:
- thirst is persistent, regardless of how much you drink
- you also have blurry vision, excessive hunger, or cuts
or sores that do not heal
- you are also fatigued
- you are urinating more than five quarts a day
To help diagnose the reason for your excessive, unresolved thirst, your
doctor will ask you for a complete medical history, including any previously
diagnosed conditions. Be prepared to list all of your prescription and
over-the-counter medications and supplements.
Some questions your doctor may ask include:
- How long have you been aware of your symptoms?
- Are you also urinating more than usual?
- Did your symptoms begin slowly or suddenly?
- Does your thirst increase or decrease during certain
times of the day?
- Have you made dietary or other lifestyle changes?
- Has your appetite for food been affected?
- Have you gained or lost weight?
- Have you recently had an injury or burn?
- Are you experiencing any bleeding or swelling?
- Have you had a fever?
- Have you been perspiring heavily?
In addition to a physical exam, your doctor may order blood and urine tests
to help provide a diagnosis. These tests may include:
- blood glucose test
- blood count and blood differential tests
- urinalysis, urine osmolality, and urine electrolyte tests
- serum electrolyte and serum osmolality tests
Depending on the test results, your doctor may refer you to a specialist.
Treatment and outlook will depend on the diagnosis.
Risks of excessive
When you try to quench excessive thirst, it’s possible to drink too much
fluid. Taking in more water than you expel is called overhydration. This can
occur when you drink too much liquid to compensate for fluid loss. It can also
occur if you have disorders in the kidney, liver, or heart.
Overhydration can cause a severely low blood sodium level
that could result in confusion and seizures, especially if it develops quickly.
How much fluid do
you normally need?
To remain healthy, you need to drink fluid regularly throughout the day. You
can increase your water intake by eating water-rich foods, such as:
A good way to know if you’re getting enough fluids is to check your urine.
If it’s light in color, high in volume, and does not have a heavy smell, you
are probably getting enough fluid.
Every organ, tissue, and cell in your body needs water. Water helps your
- maintain a normal temperature
- lubricate and cushion your joints
- protect the spinal cord
- rid your body of waste through perspiration, urination,
and bowel movements
You need to take in extra fluids when you:
- are outdoors in hot weather
- are engaging in a rigorous activity
- have diarrhea
- are vomiting
- have a fever
If you fail to replenish the fluids you lose and fail to respond to your
thirst by drinking fluids, you can become dehydrated.