Cloudy urine is usually caused by extra stuff mixed into the pee—like white blood cells, bacteria, crystals, protein, or mucus—rather than the urine itself changing color.

Common everyday causes

  • Mild dehydration – Not drinking enough makes urine more concentrated with salts and waste, which can give it a hazy look.
  • Recent sex or ejaculation – In men, a bit of semen or prostate fluid left in the urethra can mix with urine and make it look cloudy for a short time.
  • Diet and supplements – Very high intake of phosphorus (certain sodas, processed foods) or some vitamins/minerals can sometimes make urine look cloudy or more “milky.”

These causes often clear within a day or two when you hydrate and go back to your usual routine.

Infections that make urine cloudy

Cloudiness often comes from infection-related cells and debris in the urine.

  • Urinary tract infection (UTI) – One of the most common reasons: cloudy urine plus burning when peeing, going more often, strong smell, or lower belly discomfort.
  • Bladder inflammation (cystitis) – A form of UTI where the bladder lining is inflamed; often causes cloudy, smelly urine and frequent, urgent peeing.
  • Sexually transmitted infections (STIs) – Infections like chlamydia, gonorrhea, or trichomoniasis can cause genital discharge that mixes with urine and makes it cloudy; may come with genital itching, discharge, or pain when peeing.
  • Prostatitis (inflammation of the prostate in men) – Can cause pelvic pain, trouble peeing, and cloudy urine from inflammation and infection.

These usually need medical evaluation and often antibiotics.

Other medical reasons

Cloudy urine can also signal conditions beyond simple infection.

  • Kidney stones – Stones can cause blood, crystals, and inflammatory cells in urine, making it cloudy; often with severe side or back pain, nausea, or visible blood.
  • Kidney disease – Protein leaking into urine (proteinuria) can make it appear foamy or cloudy, sometimes tied to conditions like diabetes, high blood pressure, or glomerulonephritis.
  • Diabetes or high blood sugar – Poorly controlled diabetes can change urine composition and increase infection risk, both of which may lead to cloudy urine.

These causes are more likely if cloudiness is persistent and paired with other symptoms (swelling, fatigue, high blood pressure, ongoing pain).

When cloudy urine is more worrying

You should contact a doctor promptly if cloudy urine comes with:

  • Fever or feeling very unwell
  • Burning, pain, or strong urgency when peeing
  • Blood in urine (pink, red, or cola-colored)
  • Side, back, or lower belly pain
  • Nausea or vomiting
  • Cloudiness that lasts more than a few days, even with good hydration

A simple urine test (urinalysis) often pinpoints the cause and guides treatment, and most underlying problems are very treatable when caught early.

Information gathered from public forums or data available on the internet and portrayed here.