A burning sensation while passing urine is usually caused by irritation or infection in the urinary tract, most commonly a urinary tract infection, but it can also happen due to low water intake, concentrated urine, dehydration, spicy food, or sometimes sexually transmitted infections. When urine becomes more concentrated, it can irritate the inner lining of the bladder and urethra, which leads to that burning discomfort every time you urinate. Right now, the first step is to increase your water intake so the urine becomes diluted and less irritating. Try to drink fluids regularly throughout the day rather than in one go. Avoid holding urine for long periods, and reduce intake of coffee, alcohol, and very spicy foods for a few days, as they can worsen irritation. Keeping good personal hygiene also helps reduce bacterial growth. If symptoms continue for more than a couple of days, or if you notice fever, lower abdominal pain, back pain, foul-smelling urine, or blood in urine, it is important to get a urine test done and consult a doctor, as you may need specific treatment depending on the cause.