Dehydration happens when your body loses or uses up more fluids than you take in. This leaves your body short on the fluids it needs to work properly. If left untreated, long-term dehydration can raise the risk of serious harm to vital systems like your brain, heart, and kidneys.
Even if you try to drink enough water, other things can still make dehydration more likely. It can happen because of diarrhea, vomiting, fever, heavy sweating, or peeing too often. Certain illnesses that mess with how your body handles fluids can also make dehydration a bigger risk.
Symptoms of Dehydration
Spotting the signs early helps you replace lost fluids or get medical help before things get worse. Symptoms may include:
- Dark urine
- Dizziness
- Dry skin
- Feeling very thirsty
- Tiredness
- Peeing and sweating more than normal
- Dry mouth (xerostomia)
#1 Celiac Disease
Celiac disease is a long-term autoimmune disorder that harms your small intestine. It flares up when people with the condition eat gluten—a protein in wheat, rye, barley, and some other grains. The only treatment is cutting out gluten completely.
With celiac disease, gluten triggers an immune attack on the villi (tiny finger-like parts in your small intestine that absorb nutrients). Damaged villi can lead to malabsorption (trouble taking in vitamins and minerals from food).
Diarrhea is a common sign of malabsorption in celiac disease. Since diarrhea makes you lose fluids fast, dehydration can follow. In rare cases, celiac disease can cause severe diarrhea that leads to extreme dehydration, weight loss, and metabolic problems—a serious situation called a celiac crisis.
Symptoms vary from person to person. Some people have celiac disease without obvious signs. When symptoms do show up in adults, they may include:
- Stomach pain
- Bloating
- Ongoing diarrhea
- Constipation
- Gas
- Lactose intolerance
- Greasy, foul-smelling stools
- Nausea
- Vomiting
#2 Sjögren’s Disease
Sjögren’s disease (once called Sjögren’s syndrome) is a chronic autoimmune condition that affects your whole body. About half of people with Sjögren’s also have another autoimmune disease like lupus, rheumatoid arthritis, or scleroderma.
The disease causes issues when your immune system attacks glands that produce moisture—like your salivary glands (which make saliva), lacrimal glands (which make tears), and mucosal membranes (which make mucus). Sometimes, it also damages other organs and tissues.
Dehydration can happen because Sjögren’s messes with your body’s ability to balance fluids and electrolytes (minerals that help control water levels).
Other symptoms include:
- Dry cough
- Dry nose and throat
- Dry airways and digestive tract
- Dry skin
- Shortness of breath
- Fatigue
- Joint and muscle pain
- Muscle weakness
- Numbness or tingling in hands/feet
- Skin rashes
- Swollen face/neck glands
- Vaginal dryness
- Dry eyes (xerophthalmia)
- Dry mouth (xerostomia)
#3 Ulcerative Colitis
Ulcerative colitis is a type of inflammatory bowel disease (IBD) that causes inflammation and ulcers (open sores) on the inner lining of your large intestine (your colon and rectum). It usually occurs as the result of an overactive immune system.
National Institute of Diabetes and Digestive and Kidney Diseases. Ulcerative colitis.
Inflammation from ulcerative colitis can inhibit adequate water and electrolyte absorption (magnesium, sodium, zinc, phosphorus, potassium), causing dehydration. Your large intestine is responsible for water and electrolyte absorption and cannot perform this normally when it is damaged. Additional conditions common in ulcerative colitis, such as frequent and watery diarrhea, can also contribute to dehydration.
Other symptoms of ulcerative colitis can range from mild to severe. Many people have symptoms balanced by periods of remission (times when symptoms disappear). Symptoms can include:
- Abdominal cramps and pain
- Anemia (low red blood cell count)
- Bloody stool
- Fatigue and low energy
- Fever
- Loose and urgent bowel movements
- Loss of appetite
- Nausea
- Persistent diarrhea
- Tenesmus (urgent need to have a bowel movement, including when the bowel is empty)
- Unintended weight loss
#4 Cystic Fibrosis
Cystic fibrosis is a progressive genetic disease. In people with cystic fibrosis, mutations in a gene called the cystic fibrosis transmembrane conductance regulator (CFTR) damage the CFTR protein. When this protein is dysfunctional, it cannot move chloride, a component of salt, to the cell surface. Without chloride to attract water to the cell surface, the mucus in various organs becomes thick and sticky.
People with cystic fibrosis have a higher risk of dehydration because they lose more sodium (salt) from their bodies than the average person. When a person with CF is active in recreational activities, becomes ill, or the weather is excessively hot, they lose more sodium (salt) from their body than the average person.
People with cystic fibrosis also have a thirst sensation that does not turn on as efficiently as it does for other people. Usually, salt levels in your blood climb when you sweat, triggering thirst. However, when too much salt is lost, as occurs in cystic fibrosis, you may not feel thirsty even if you have lost a lot of body fluid.
Other symptoms of cystic fibrosis can occur as a result of mucus that becomes thick and sticky rather than thin and slippery. Thick mucus can cause blockages and clog your organs. This interferes with normal organ function and leads to:
- Diabetes
- Diarrhea
- Difficulty breathing
- Fertility problems
- Frequent lung infections
- Malnutrition
- Pancreatic failure
- Permanent lung damage
- Unintended weight loss
#5 Crohn’s Disease
Crohn’s disease is a chronic inflammatory bowel disease that affects the gastrointestinal (GI) tract. It can cause inflammation in any part of the tract but usually affects the small intestine and the top of the large intestine. Research indicates that Crohn’s disease may be an autoimmune disease, though its specific cause is unknown.
Diarrhea and vomiting associated with Crohn’s disease can lead to severe dehydration in some people. Dehydration in Crohn’s disease occurs when you lose more fluids than you replace. Dehydration can be a life-threatening condition if left untreated.
Other symptoms of Crohn’s disease can include:
- Abdominal pain
- Anemia (low iron levels)
- Bloating
- Diarrhea with or without blood
- Fatigue
- Floating stools as a result of poor fat digestion
- Nausea and vomiting
- Poor appetite
- Unintended weight loss
#6 Diabetes
Diabetes is a chronic disease that interferes with your body’s ability to convert food into energy. When you eat, your body breaks down the food you consume into glucose, a type of sugar. When this sugar enters your bloodstream, your pancreas releases insulin, a hormone that pushes sugar into your body’s cells so they can make energy.
Diabetes can interfere with the production of an adequate amount of insulin or the proper use of insulin. This leaves too much glucose in your bloodstream, without it reaching your cells.
Diabetes can increase your risk of dehydration because your kidneys typically reabsorb blood sugar. However, the elevated blood sugar levels that occur with diabetes can stress your kidneys.
As a result, the extra sugar passes into your urine along with extra fluid, making you urinate more frequently. Your body draws fluid from your cells if you are not drinking enough to replenish the extra fluid needed to flush out the extra sugar. As you excrete more fluid than you consume, dehydration can occur.
Other symptoms of diabetes include:
- Blurry vision
- Constant hunger
- Dehydrated skin
- Fatigue
- Frequent infections than usual
- Frequent urination, often at night
- Numbness or tingling in your hands or feet
- Polydipsia (excessive thirst)
- Slow-healing sores
- Unintended weight loss
#7 POTS Syndrome
POTS (postural orthostatic tachycardia syndrome) is a blood circulation disorder. It is one of a group of conditions characterized by orthostatic intolerance, which causes tachycardia (rapid heart rate) and a drop in blood pressure when moving from a seated or lying position to a standing position.
Problems occur because your body cannot control your blood pressure or heart rate after you rise. For up to 10 minutes after you stand, you may not get enough blood to your brain, resulting in dizziness and light-headedness.
Dehydration can occur in POTS because the condition interferes with your ability to retain fluids. One common problem involves the kidney hormones aldosterone, angiotensin, and renin, which regulate sodium and fluid retention. When inadequate fluid remains in your bloodstream, the reduced blood volume contributes to POTS syndrome
Other symptoms of POTS can include:
- Chest pain
- Coldness or pain in the extremities
- Drop in blood pressure upon standing
- Dyspnea (shortness of breath)
- Exercise intolerance
- Fatigue
- Headaches
- Heart palpitations
- High levels of plasma norepinephrine upon standing
- Hypovolemia (low blood volume) upon standing
- Nausea
- Presyncope (light-headedness)
- Reddish purple color in the legs upon standing that subsides upon returning to a reclined position
- Syncope (fainting)
- Tremulousness (shaking)
#8 Cancer
Cancer occurs when some of your body’s cells mutate, grow uncontrollably, and spread to other parts of your body in a process called metastasis. The disease can start anywhere in your body. Cancer cells grow and multiply when they should not. Problems arise when these cells join together and form tumors or lumps, which can be benign (noncancerous) or malignant (cancerous).
Your fluid needs can be affected by the type of cancer you have. For example, people with gastrointestinal cancers have a higher than normal risk of dehydration due to factors such as nausea, vomiting, diarrhea, or trouble swallowing.
Other symptoms of cancer can vary based on the location of the cancer cells. Some common symptoms of cancer are:
- Abdominal pain
- Bladder changes or passing blood during urination
- Change in normal bowel habits leading to constipation or diarrhea
- Fatigue
- Loss of appetite
- Nausea
- Swelling, lumps, thickening, or other skin changes anywhere in your body
- Trouble swallowing
- Unintended weight loss of 10 pounds or more
- Unusual bleeding or bruising for no reason
- Vomiting
#9 Addison’s Disease
Addison’s disease is a rare condition also known as primary adrenal insufficiency and hypocortisolism. With this disease, your adrenal glands do not produce enough of the hormones cortisol and sometimes aldosterone. Your adrenal glands sit just above your kidneys. The most common cause of the disease is autoimmune adrenalitis, a disorder in which your immune system attacks cells of your adrenal glands.
Addison’s disease and a shortage of cortisol can interfere with your body’s ability to respond to stress and perform other normal life functions. Dehydration can occur as an early sign of Addison’s disease. It is linked to insufficient levels of the hormone aldosterone, which regulates the balance of salt and water in your body.
Other symptoms of Addison’s disease are:
- Craving salty foods
- Fatigue
- Frequent urination
- Increased thirst
- Irritability or low mood (mild depression)
- Lethargy (drowsiness or a lack of energy or enthusiasm)
- Loss of appetite
- Muscle weakness
- Unintended weight loss
#10 Gastroenteritis
Gastroenteritis is a short-term illness caused by inflammation of the lining of the stomach and intestines. While it is often referred to as the “stomach flu,” gastroenteritis is not caused by flu viruses. It can be caused by many different viruses, including noroviruses and rotaviruses. It can also occur as a result of consuming food or drinks contaminated with viruses, bacteria, parasites, or chemicals, a condition called food poisoning.
While gastroenteritis is not harmful to most people, it can become dangerous if it leads to dehydration. Dehydration is the most common complication of gastroenteritis because of the loss of fluids and electrolytes that occur with diarrhea and vomiting.
In addition to dehydration, other symptoms of gastroenteritis are:
- Abdominal pain or cramping
- Nausea or vomiting
- Occasional fever33
- Watery diarrhea
#11 Hyperthyroidism
Hyperthyroidism is a condition characterized by an overactive thyroid gland. It results in the overproduction of thyroid hormones. This can speed up your body’s metabolism and its processes. While the condition can give you extra energy, it eventually causes fatigue because your body is not intended to maintain normal function at this accelerated rate.
Dehydration can be a complication of hyperthyroidism due to high body temperatures, sweating, and diarrhea. It can also occur as a symptom of a thyroid storm, a rare but life-threatening condition that causes severe dehydration and cardiac problems.
Other symptoms of hyperthyroidism are:
- Anxiety
- Heart palpitations
- Increased appetite
- Irregular and/or rapid heartbeat
- Sleep problems
- Unintended weight loss
#12 Sepsis
Sepsis, also called blood poisoning, is your body’s extreme response to an infection. It is a life-threatening medical emergency that damages vital organs and tissue. Sepsis requires immediate medical treatment.
Dehydration occurs with sepsis due to the external loss of fluid through sweating. Sepsis also causes internal fluid loss due to decreased oral intake of fluids, capillary leakage, and sepsis-induced vasodilation (widening of blood vessels to increase blood flow to areas lacking nutrients or oxygen).
Get immediate medical attention if you or a family member is experiencing any of the following symptoms of sepsis:
- Clammy or sweaty skin
- Confusion or disorientation
- Extreme pain or discomfort
- Fever, chills, or feeling very cold
- Rapid heart rate and breathing
- Shortness of breath
IV Treatments or Drinking Water: What’s the Best Treatment for You?
The best treatment for dehydration depends on the severity of the symptoms and the cause of the dehydration. Intravenous (IV) fluid replacement is routinely provided in hospitals to deliver large quantities of liquids directly into the bloodstream of severely dehydrated patients. More recently, it has also been provided at “drip bars,” locations where you can receive IV fluids without a physician’s recommendation.
While water can help replenish fluids lost to dehydration, IV therapy can replace fluids faster and in greater quantities. IV therapy also provides an option to add lost vitamins, minerals, and electrolytes, as well as medications. to help your body heal.
When necessary, IV treatments are prescribed by a healthcare provider and administered by a medical professional trained in inserting an IV and monitoring your response to treatment. The option may be especially beneficial to populations such as older adults and the chronically ill, who cannot replenish lost fluids solely through drinking water.
While IV therapy may also benefit other patients, the Federal Trade Commission (FTC) previously challenged claims by an IV therapy company that marketed its cocktails to treat chronic diseases. The FTC warned that health claims made by IV therapy drip bars must be supported by “competent and reliable scientific evidence.
If you have symptoms of dehydration, contact your healthcare provider for advice on restoring lost fluids and other treatments. Dehydration resulting from an acute or chronic medical condition may also require other medical treatments to offset complications and promote healing.
Final Notes
Dehydration strikes when your body loses more water than it takes in. Without enough fluids, your body can’t function right. While mild cases can be fixed by drinking more, severe dehydration needs medical care.
You can help prevent it by staying on top of fluids and watching for early signs like dry mouth, dizziness, and fatigue. Some health conditions make dehydration more likely, even if you drink enough. Knowing the symptoms helps you get treatment fast.