It can be really embarrassing to talk about bodily fluids, especially semen. It’s hard to know what normal semen is supposed to look like, mostly because no one is actually talking about it. We want to change that. It’s time to get impolite. Let’s talk about what’s normal semen and what your semen quality could be telling you about your health.
A pretty common question that we get on this site is “What’s semen made out of?”. So before we get into the thick of things, here are some basics about semen:
Semen is composed of several different fluids. Roughly 70% of your semen is fluid from the seminal vesicles, roughly 20% is fluid from the prostate and 5% is fluid from the testicle and epididymis, where the actual sperm are, and roughly 1% is bulbourethral fluid. The seminal and prostatic fluid function as a sort of food and force field for sperm. They both contain salts and sugars to nourish the sperm, as well as amino acids and zinc to protect the sperm from the harsh outside environment. Meanwhile the bulbourethral fluid makes the semen jelly-like and therefore easier for sperm to swim in.
Normal, healthy semen is a cloudy grayish-white to slightly yellow color. Any other colors mean you should probably have a chat with your doctor. Semen that’s a deep yellow or green could be indicative of an infection, or urine in your semen. Semen that’s a pink color to a reddish brown is the result of blood in your semen, and could be a sign of prostate problems.
Normally, semen should smell a little bit like chlorine or bleach. If you’ve noticed your semen has begun to smell a little…pungent, this could be a sign of infection and you should consult your doctor as soon as possible.
When first ejaculated, semen should be fairly viscous, similar to (we’re so sorry to ruin this for you) egg-whites, this is due largely to the bulbourethal fluid that it contains. After roughly 30 minutes, semen starts to lose its viscosity, becoming thinner and runnier. This is due to prostate specific antigen (PSA), an enzyme found in prostatic fluid whose main purpose is to assist in the keeping sperm higher in the woman’s vagina after ejaculation. Semen that doesn’t liquefy after this time period could be as a sign of a prostate problem and reduce your sperm motility.
Semen’s viscosity (thickness) is a bit of a balancing act. While many men associate thick semen with masculinity, semen that is too thick means the sperm can’t escape the fluid and start the long, hard trek to the egg. Thick ejaculate could be a sign of low testosterone or an STI. If semen is too thin or “watery” immediately after ejaculation, this could be a sign of retrograde ejaculation or an ejaculatory duct obstruction.
Much like sperm count, semen viscosity can vary greatly from day to day. Several different factors affect it, including hydration (dehydration tends to make semen thicker), frequency of ejaculation (the more you ejaculate, the thinner your semen becomes. There’s only so much in the tank!) and infection (your semen will be thicker of clumpier if you’ve recently had a cold, or if you have an untreated STI).