Male fertility
Viscosity describes the stickiness or thickness of semen once it has liquefied. Semen that remains abnormally thick or stringy (high viscosity) can trap sperm and make it harder for them to move freely, and can also interfere with accurate laboratory measurement of concentration and motility. High viscosity does not necessarily mean sperm are unhealthy; laboratories can use techniques to reduce viscosity before analysis, and the underlying semen quality is then assessed on the corrected sample.
Also known as: semen thickness, sticky semen
Sources
- World Health Organization (who.int)
Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.