Clear, Frequent Urination (Polyuria): 6 Main Causes & When to Worry.
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The short answer:
Common causes of clear urine with frequent urination are over-hydration, caffeine, undiagnosed or uncontrolled diabetes mellitus, diabetes insipidus, kidney diseases, and others.
- The combination of clear (diluted, water-like) urine and frequent urination is called (poluria).
- Occasional polyuria is common, typically due to excess fluid intake, diuretic medications, excess alcohol, caffeine, or during pregnancy.
- However, it may also mean a disease such as diabetes mellitus, diabetes mellitus, diabetes insipidus, kidney diseases, hypercalcemia, Cushing’s syndrome, etc.
- Consider seeing a doctor if you have:
Table of Contents
Clear or light-colored urine may indicate that you drink too many fluids, such as water or other beverages. Eating certain high-water fruits such as watermelon can also lead to more frequent urination and clear urine.
This is the most common cause of occasional clear urine. Clear urine (like water) occurs due to diluting the yellow pigments, making your pee very light in color.
- Extreme thirst, followed by drinking large amounts of water.
- Habitual drinking of water without being thirsty.
- Too many fruit juices.
- Drinking too much alcohol or beer.
- Too much soda or carbonated drinks.
- Eating Too many high-water fruits (such as watermelons, oranges, etc.).
Clear urine doesn’t necessarily mean a kidney problem. It may be due to simple causes such as excess water or other fluids. Urine is supposed to revert to its standard yellow color within a few hours or a day.
 Caffeine or Excess Alcohol.
Caffeine and clear urine:
Caffeine is a potent diuretic; drinking coffee will increase your urine output and may cause clear urine without drinking water. The effect of caffeine is dose-dependent; The more caffeine you drink, the more polyuria and clear water-like urine you will get.
Alcohol and clear urine.
Alcohols with high alcohol consumption increase the amount of urine, leading to clear or white urine. Also, Binge drinking of low-alcohol or non-alcoholic beer can produce the same effect (due to over-hydration).
 Diabetes Mellitus (undiagnosed or uncontrolled).
Diabetes mellitus refers to the increase in blood sugar (glucose) levels. Patients with undiagnosed diabetes often present with polyuria (frequent urination of large amounts of clear urine without drinking water), thirst sensation, and progressive weight loss.
Also, clear urine may mean uncontrolled diabetes if you are known to be diabetic. High blood sugar diabetes causes polyuria because your body excretes excess sugar through the kidneys.
As the excess blood glucose passes into the urine, it causes the urine volume to increase and the color of pee to pale yellow or clear white (glucose draws more water from the body into the urine).
Other symptoms of diabetes:
- Polyphagia: Persistent or recurrent hunger despite eating well.
- Polydipsia: Thirst sensation despite drinking water.
- Headache and dizziness.
- Peeing a lot of urine (typically clear and diluted).
- Sweet urine smell.
Many medications are intended to increase urine volume (diuretics). Also, some medications may lead to polyuria (frequent urination) as a collateral effect.
Medications that increase urine output produce pale yellow or clear white urine according to its potency and dose.
- Diuretics such as furosemide (Lasix@), Aldactone, hydrochlorothiazide etc.
- Some antihypertensive medications include Cardura, Amlodipine (Norvasc®), and Felodipine (Plendil®).
- Some diabetes medications such as Dapagliflozin (Farxiga), canagliflozin (Invokana®), and empagliflozin (Jardiance).
- Tamsulosin (Flomax®) is used to treat prostatic hypertrophy (BPH).
- Antidepressants such as escitalopram, sertraline, and fluoxetine.
- Benzodiazepines (for treatment of insomnia and anxiety) such as diazepam (Valium®).
 Diabetes Insipidus (the central type).
A deficiency of antidiuretic hormone (secreted inside the brain), leads to the inability of the kidney to concentrate urine (excess crystal clear urine). ”This type of DI is due to a lesion in the brain (hypothalamus) rather than a kidney disease).
Symptoms of central DI:
- Peeing large volumes of urine (polyuria).
- Diluted (crystal-clear, water-like urine).
- Frequent waking up to pee (nocturia).
- Thirst sensation and frequent water drinking (polydipsia).
- Bone pain, easy fractures (in prolonged cases).
Causes of central DI:
- Unknown (in 30-50% of the cases).
- Inherited (genetic defects).
- Brain trauma or surgery.
- Cancers (primary brain cancers or brain Mets).
- After supraventricular tachycardia.
- Anorexia nervosa.
- Severe oxygen drop (hypoxia).
 Kidney diseases (nephrogenic diabetes insipidus).
It is considered a kidney disease (not a kidney failure, but a kidney defect leading to the kidney’s defective ability to concentrate urine.
Nephrogenic diabetes insipidus occurs due to kidney resistance to the antidiuretic hormone (ADH), which is necessary to control the amount of urine.
Common causes of nephrogenic DI:
- Genetic mutations (inherited from parents).
- Chronic kidney diseases: bilateral urinary tract obstruction, sickle cell disease, Sjogren’s syndrome.
- Polycystic kidney disease.
- Chronic lithium use and Nonsteroidal anti-inflammatory drugs (NSAIDs).
- Renal amyloidosis.
- Severe hypercalcemia.
- Severe hypokalemia.
- Hypercalcemia (increased blood calcium, typically due to parathyroid adenoma or due to malignant tumors such as multiple myeloma.
- Pregnancy (especially the third trimester).
- Cushing syndrome
- Healing from kidney disease.
- Steroid therapy.
- High protein diet.
- Excess intravenous fluids.
- Mannitol and hypertonic saline are used for people with brain diseases such as cerebral hemorrhage.
- Psychogenic polydipsia.
When to see a doctor?
- A persistent large volume of crystal-clear urine.
- Recurrent thirst sensation.
- Persistent hunger despite of eating well.
- Weight loss or weight gain.
- Frothy or foamy urine.
- Flank (kidney) pain or burning urination.
- Nausea or vomiting.
- Severe headache or dizziness.
- Written by a doctor.
MD, Internal Medicine and Nephrology specialist.
Dr. Esraa A. MagidAuthor