It's a subject that rarely comes up in conversation, but your pee could actually hold the key to your health. Gastroenterologist Dr. Anish Sheth, co-author of What's My Pee Telling Me?, breaks down what looking into the toilet bowl might reveal.

Is there a difference in male and female urine?

Dr. Sheth: "The main interesting thing about women and urine is urinary tract infections. It's actually decidedly uncommon for men to get infections in the urine, but I'm sure most women have had at least one, if not more than one, urinary tract infections (UTI). The reason for that is the female urethra is much shorter and bacteria can travel up into the urinary tract and the bladder.

"The signs of UTI include peeing more frequently, a different odor, a burning sensation, or even sometimes blood in the urine. If you do have reoccurring infections, there is a compound in cranberry juice that actually prevents the bacteria from attaching to the bladder wall. So if you are somebody who has frequent UTI, a glass a day can actually help considerably."

What does the strength of your pee stream mean?

Dr. Sheth: "As we get older, the strength of both men's and women's streams actually decline. In men, it’s because of something called BPH, Benign Prostatic Hypertrophy. This is when the prostate gland gets bigger and actually prevents urine from coming out and it can be quite problematic. In women, especially once you get past childbearing age, there is something called Pelvic Floor Dysfunction, where the muscles in the pelvis become weak ... and the urinary stream can actually drop off. So as we get older, we should pay attention to the stream - if you notice that it's not coming out with as much velocity as a few years back, then it might be a sign that something is wrong."

Should the amount of urine that comes out be the same as the amount of liquid you consume?

Dr. Sheth: "Actually, your urine output is pretty constant, about 1.5 liters a day, which turns out to be a little more than a quart (about 40 ounces or so). In order to get rid of the other waste that's in urine, your kidneys need to filter that much water. If you're taking medication or have other issues, diuretics for instance, those people will go more.

"The issue of how much water you drink is a great question. Eight glasses a day is probably a bit of overkill, because you actually get water in food and other things we ingest. That number comes from how much we lose on a daily basis. Assuming you’re not running a marathon and just going about daily life, you're going to sweat a certain amount in your breathing, emit water vapor a little bit and lose some in your urine. So when you put that together, it comes to eight glasses a day. It's a good metric but you don’t have to go crazy with measuring things out; as long as your urine looks the right color." Check out the gallery to the right to see what the color of your pee could be telling you.

Can certain foods make your pee smell, and is that normal?

Dr. Sheth: "Asparagus aftershock is widely known ... a foul, eggy aroma. Amazingly, it's just part of normal digestion. So about 15 minutes after you eat asparagus, the odor can end up in your urine. Interesting tidbit, if you cut the tips off the asparagus, the odor goes away.

"Sometimes urine can smell fruity. And while that may be pleasant, more pleasant than asparagus, it actually can be the first sign of diabetes. The product is called ketones, which our body makes when our blood sugars are very high, and those ketones lend your urine a berry type of aroma. That's when changes in smell can be a health issue and you want to get that checked out by a doctor."

Sometimes my pee is just a little bit bubbly. What does that mean?

Dr. Sheth: "A lot of us, especially men, when you pee and the pee hits the water, it's turbulent and you get bubbles. When it seems excessive (you look down and there’s a bubble bath in your toilet), it may be a cause for concern. There are actually conditions of the kidney in which proteins escape the body and actually make their way into the urine. And when you have a lot of protein in your urine, your urine looks bubbly. It can be a sign that there is damage to the kidneys, usually from long-standing diabetes or high blood pressure. So I would say if it happens once in a while, don’t worry about it. But if you see it consistently, especially if you're being treated for high blood pressure or diabetes, you may want to get something called a urine dip stick test, where you can actually test to see if there are proteins in the urine. It's an easy test and you can go to the doctor for it."

Is it true that if you pee on your skin it has benefits?

Dr. Sheth: "Absolutely. Urine is mostly water, as you can imagine. But 2.5 percent by concentration is something called urea. Urea is a normal byproduct of our body, and if you look at the label on a lot of the lotions you use, urea is an active compound. Actually, a lot of professional athletes and baseball players use it to prevent calluses. Urea is also found in a lot of over-the-counter athletes foot preparations."