why does period blood smell

Period blood smells due to the presence of iron in the blood combined with the natural bacteria in the vagina, hormonal changes, and the vagina's acidic environment. Fresh menstrual blood has a mild metallic smell because of the iron content. When the blood stays in the vagina for a while, it mixes with bacteria which can cause a musky or slightly stronger odor. This smell can also be influenced by sweat glands in the genital area, hygiene, and how long blood or period products are left in place. If the smell becomes very strong, foul, fishy, or rotten, it may indicate an infection like bacterial vaginosis or that a tampon has been left in too long, requiring medical attention. Normal period blood smell is typically mild and metallic, and variations are often due to natural factors or minor hygiene issues.