Urine

What is urine?

Urine (pee) is liquid waste that your kidneys create after they filter your blood. After your kidneys produce urine, it travels throughout the rest of your urinary system:

• It moves from your kidneys to your bladder through your ureters.
• Your bladder holds your urine until you’re ready to use the restroom (urinate).
• Your bladder squeezes (contracts) and urine flows through your urethra and out of your body.

Some find urine gross, or getting up to use the bathroom may be a chore (especially if you’re half asleep). But urine is very important to maintaining your health. Changes to your pee can also be a sign that something in your body isn’t right.

What is urination?

Urination is the act of releasing urine from your body.

What is urine’s purpose?

Urine has many purposes. It helps:

• Remove wastes from your blood
• Control the amount of blood in your body (blood volume)
• Regulate your blood pressure
• Keep your blood chemistry in the normal range

What is in pee?

Between 91% and 96% of healthy urine is excess water. The rest consists of:

• Salt (sodium)
• Urea (a protein waste product)
• Uric acid (a nitrogen waste product)
• Electrolytes, including potassium and phosphorus

But if your kidneys aren’t working as expected, your urine may include excess toxins, protein and even blood (hematuria).

What color pee is healthy?

Healthy urine should be light yellow, like the color of light straw or lemonade. It means you’re drinking enough water, and nothing is visibly wrong with your pee, such as foamy, bubbly or bloody pee.

What makes urine yellow?

Urochrome (urobilin) is a chemical that forms when protein metabolizes in your liver. It gives urine its yellow color.

What color is urine when your kidneys are failing?

Urine may be dark yellow, brown or even reddish if you have kidney failure. It may also be foamy or bubbly, and the amount you pee may decrease.

What are the common conditions and disorders that affect urine?

Many conditions may cause urine changes, including changes to its appearance, color or smell. Some of these include:

• Urinary tract infections (UTIs)
• Kidney stones
• Dehydration
• Liver disease
• Porphyria
• Chronic kidney disease (CKD)
• Bladder cancer or kidney cancer
• Lead poisoning or mercury poisoning
• Diabetes
• Inborn errors of metabolism

Why is my urine yellow and smelly?

It’s normal for your urine to have a mild smell. But if your urine is darker yellow and smells stronger than usual, it may be your body’s way of telling you that something is wrong.

One of the more common causes of smelly, darker yellow urine is dehydration. When you don’t drink enough water, the amount of waste products in your pee increases. High levels of urea can make your urine smell like ammonia.

The following may also cause changes to the color and/or smell of your urine:

• Urinary tract infections. The bacteria that cause UTIs can make your urine darker and smell.
• Sexually transmitted infections (STIs). STIs such as chlamydia, gonorrhea and trichomoniasis can cause foul-smelling urine or discharge. 
• Medications. Medications that contain sulfonamides (sulfa) can make your pee smell like rotten eggs as your body breaks down sulfa into sulfur. Sulfa is common in many antibiotics. Phenazopyridine can also turn your pee bright orange.
• Vitamin supplements. Your body removes extra vitamins it doesn’t need through your urine. B-complex vitamins can turn your urine bright yellow and make it smell fishy or musty. Vitamin C can make your urine look dark yellow or orange.
• Certain foods. Eating a lot of asparagus, garlic, Brussels sprouts and curry can cause your urine to smell different than usual. Eating lots of carrots can make your urine look dark yellow or light orange.

What does unhealthy urine smell like?

In general, most people would say urine always has an unpleasant smell. But the smell of unhealthy urine is noticeably different, and the exact type of smell depends on the cause. For example, an infection may cause your urine to smell like rotten eggs or rotting fish. But if you have diabetes or a condition that affects your metabolism, your urine may smell sweet.

Reach out to a healthcare provider if you notice your urine smells noticeably different than usual and you’re not sure why.

What does bad kidney pee smell like?

Chronic kidney disease may cause your urine to smell like ammonia.

What are common tests to check urine?

A urinalysis (pee test) is the gold standard for analyzing urine. You’ll urinate into a specimen cup, and a healthcare provider or laboratory technician will examine its color and appearance. They’ll also look at its chemical and microscopic components under a microscope.

How often should I pee every day?

It depends. Most adults typically urinate between six and seven times a day. But you may pee more or less according to:

• Your age
• How much you drink each day
• What fluids you drink
• What medications you take
• Whether you have certain conditions, such as a UTI

Talk to a healthcare provider if you have any concerns with how much you urinate each day.

What makes you pee more?

There are many possible causes of frequent urination, including:

• Pregnancy
• Diabetes
• Enlarged prostate (benign prostatic hyperplasia)
• Certain medications, including diuretics
• UTIs

Certain beverages can also make you pee more often, including:

• Alcohol
• Caffeine, including coffee, energy drinks, tea and soda pop
• Citrus fruits, including oranges, lemons, limes and grapefruits

What makes you pee less?

Common causes of low urine output (oliguria) may include:

• Dehydration
• Vomiting
• Diarrhea
• Blockages in your urinary system, such as a urethral stricture, BPH, bladder outlet obstruction, ureteral obstruction, cystocele or rectocele
• Certain medications, including antihistamines, opioids, tricyclic antidepressants and muscle relaxers
• Conditions that affect your nerves, including stroke, diabetes, spinal cord injury, vaginal childbirth and multiple sclerosis (MS)
• Infections
• Surgery in the area

Does urine come from blood?

Yes. Your kidneys produce urine by filtering out excess water and wastes from your blood.