Lochia in the context of "Obstetrics"

Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of hormones. Menstruation is triggered by falling progesterone levels, and is a sign that pregnancy has not occurred. Feminine hygiene products are used in order to maintain hygiene during menses.

The first period, a point in time known as menarche, usually begins during puberty, between the ages of 11 and 13. However, menstruation starting as young as eight years would still be considered normal. The average age of the first period is generally later in the developing world, and earlier in the developed world. The typical length of time between the first day of one period and the first day of the next is 21 to 45 days in young women; in adults, the range is between 21 and 35 days with the average often cited as 28 days. In the largest study of menstrual app data, the mean menstrual cycle length was determined to be 29.3 days. Bleeding typically lasts two to seven days. Periods stop during pregnancy and typically do not resume during the initial months of breastfeeding. Lochia occurs after childbirth. Menstruation, and with it the possibility of pregnancy, ceases after menopause, which usually occurs between 45 and 55 years of age.

Postpartum bleeding or postpartum hemorrhage (PPH) is significant blood loss following childbirth. It is the most common cause of maternal death worldwide, disproportionately affecting developing countries. Definitions and criteria for diagnosis are highly variable. PPH is defined by the World Health Organization as "blood loss of 500 ml or more within 24 hours after birth", though signs of shock (insufficient blood flow) have also been used as a definition. Some bleeding after childbirth is normal and is called lochia. It is difficult to distinguish lochia from delayed PPH.

Signs and symptoms of PPH may initially include: an increased heart rate, feeling faint upon standing, and an increased breathing rate. As more blood is lost, the patient may feel cold, blood pressure may drop, and they may become restless or unconscious. In severe cases circulatory collapse, disseminated intravascular coagulation and death can occur. The condition can occur up to twelve weeks following delivery.

A menstrual pad is an absorbent item worn in the underwear when menstruating, bleeding after giving birth, recovering from gynecologic surgery, experiencing a miscarriage or abortion, or in any other situation where it is necessary to absorb a flow of blood from the vagina. A menstrual pad is a type of menstrual hygiene product that is worn externally, unlike tampons and menstrual cups, which are worn inside the vagina. Pads are generally changed by being stripped off the pants and panties, taking out the old pad, sticking the new one on the inside of the panties and pulling them back on. Pads are recommended to be changed every 3–4 hours to avoid certain bacteria that can fester in blood; this time also may differ depending on the kind worn, flow, and the time it is worn.

Menstrual pads are made from a range of materials, differing depending on style, country of origin, and brand. The pads are not the same as incontinence pads, which generally have higher absorbency and are worn by those who have urinary incontinence problems. Although menstrual pads are not made for this use, some use them for this purpose.