Urea, together with water and other waste substances, forms the urine as it passes through the nephrons and down the renal tubules of the kidney. From the kidneys, urine travels down two thin tubes called ureters to the bladder. The ureters are about 8 to 10 inches long. Muscles in the ureter walls constantly tighten and relax to force urine downward away from the kidneys. If urine is allowed to stand still, or back up, a kidney infection can develop. Small amounts of urine are emptied into the bladder from the ureters about every 10 to 15 seconds.
When to see a doctor. Make an appointment with your doctor. If tension headaches disrupt your life or you need to take medication for your headaches more than twice a week, see your doctor. Even if you have a history of headaches, see your doctor if the pattern changes or your headaches suddenly feel different.
Tension headaches are very common, unfortunately, they're also among the most neglected and difficult headaches to treat. With a tension headache, the pain often starts at the back of your head and moves forward, so that it eventually includes your neck, scalp, and head. Itâs often described as feeling like you have a tight band across your head.