Many men worry about the health of their sperm, particularly if they are trying to conceive. The factors that determine if a man’s semen is normal include the color, consistency, smell, volume, sperm concentration and percentage of abnormalities. Normal semen should have a cloudy, thick consistency that thins and clears within half an hour, and may even have a slight chlorine smell. At least 50% of the sperm should have normal motility and morphology.
Normal semen is usually a white or grey at first. It will typically thicken, then liquefy and turn clear. This change usually happens within half an hour. If the semen remains thick, there may be a problem with dehydration, but this problem normally clears on its own. If it does not return to normal after a few weeks, a more serious problem may be at hand. Furthermore, semen that is tinted red or yellow is normal, but if the discoloration is pronounced and followed by a foul smell, there may be an infection, or on rare occasions, cancer.
The amount ejaculated should be between 1.5 ml to 6ml with anywhere between 20 million to 150 million sperm. A consistently low volume of semen may indicate other health problems, such as diabetes, prostate infection or something blocking the seminal vessel. Typically, older men over 40 will have semen volumes on the lower end of the scale.
Motility and morphology are particularly important factors for determining normal semen for fertility. The percentages that scientists typically look for vary, but on average, at least a total of 50% of the sperm should have both normal motility and morphology. It is not unusual, however, for a man to have normal semen, but have just over 30% of the sperm with normal morphology. The best way to determine if a man falls within this range is through semen analysis.
If a man suspects that he may have abnormal semen, he may wish to undergo a semen analysis. Most labs request that a man abstain from ejaculation for anywhere between two and five days, and for the most accurate results the semen is analyzed within one or two hours. On some occasions, a lab may even request that the test be repeated one or two additional times within a three month period. Usually, they are only testing for normal motility and morphology, and while this is a major factor determining normal semen, it is not always indicative of fertility.