Why can urine have an odor?

The smell of urine varies depending on hydration level, diet, medications taken, and overall health status. Urine consists of 95% water, while the remaining 5% includes salts, urea, creatinine, and other metabolic substances that can affect its color and smell.
Dehydration makes urine more concentrated and darker. Foods such as asparagus, garlic, onions, fish, and spices release compounds that temporarily alter the odor. B vitamins and antibiotics can also influence urine smell.
How to recognize warning signs?
If back pain is accompanied by an unpleasant urine odor, it is important to assess the nature of this condition. The situation becomes clearer if the following symptoms also appear: fever or chills; lower back pain localized under the ribs, deep and not relieved by movement; mid-back pain indicating kidney involvement even in the absence of obvious urinary symptoms; cloudy, blood-tinged, or very dark urine; nausea and vomiting; intense thirst and frequent urination.
Kidney stones, in addition to lower back or side pain, may cause blood in the urine and an unusual odor. Diabetes can give urine a sweet or fruity smell.
If these signs are present, it is necessary to consult a doctor, who will typically perform a physical examination, ask about your symptoms, and order a urinalysis to confirm the presence of infection and assess its severity.
What should be done immediately?
Helpful measures include drinking 1.5–2 liters of water per day, limiting foods that intensify urine odor, maintaining proper personal hygiene, and avoiding prolonged retention of urine. If symptoms persist or worsen, you should consult a urologist. Early diagnosis allows timely treatment of infections or stones, helping to avoid potentially serious complications.
The exact location of back pain depends on how far the infection has spread. Lower urinary tract infections usually affect the urethra and bladder, while upper urinary tract infections may also involve the ureters and kidneys. When the bladder is affected, pain is usually localized in the lower back; however, when the kidneys are involved, the pain is typically felt in the upper back.
Back pain caused by a urinary tract infection is often described as dull. Some patients characterize it as constant pain or a throbbing sensation that becomes more noticeable when touching or pressing on the affected area of the back.
How is it treated?
For lower urinary tract infections, which are usually mild and bacterial in nature, oral antibiotics are prescribed. In more severe cases, especially when the infection causes upper back pain, intravenous antibiotics may be required. Over-the-counter pain relievers such as ibuprofen may temporarily ease pain but do not cure the infection.
If the cause is kidney stones, specific treatment methods are required and should always be discussed with a doctor. Treatment of kidney stone disease may include medication and/or surgical intervention. Sand and small stones can be eliminated with the help of medications. In cases of large stones, minimally invasive surgical techniques are used.