Strong-smelling urine is commonly caused by concentrated urine, which happens when there is less water and more waste products like ammonia present in the urine. Dehydration is a frequent reason for this concentration, making urine darker and stronger smelling. Certain foods (such as asparagus, coffee, garlic, and Brussels sprouts), vitamins (like B and D vitamins), and medications (such as antibiotics and sulfa drugs) can also cause urine to smell stronger. Sometimes, a strong urine odor can be a sign of health conditions, including urinary tract infections, diabetes (which may make urine smell sweet), liver or kidney disease, or other metabolic disorders. If the strong smell persists or is accompanied by other symptoms, it is advisable to seek medical advice.