Vaginal discharge is essential for the proper functioning of the female reproductive system, lubricating, cleansing and maintaining the microbiota. Its appearance changes throughout the menstrual cycle and, in most cases, these variations are completely normal. The presence of brown discharge, however, is always a cause for concern. The reality is that this phenomenon can have multiple explanations, from the simplest and most physiological to others that require medical evaluation.
What is brown discharge and why does it occur?
Brown discharge" occurs, in most cases, when vaginal secretions mix with old blood. Over time, the haemoglobin oxidises and the colour of the blood darkens to a brownish hue.
This happens especially when bleeding is very little or slow, as the blood takes longer to come out and oxidises before it is expelled.
What are the causes of brown discharge?
Brown discharge can occur for a variety of reasons, from physiological processes to disorders that require medical follow-up. Among the most common causes are:
- Start and end of the rule: At this time the blood flows more slowly and oxidises before it leaves.
- Ovulation: some women have slight bleeding that may look like this.
- Hormonal contraceptives: especially during the first months of use.
- Gynaecological examinations or sexual intercourse: small lesions on the cervix may cause light bleeding.
- Gynaecological disorders: polyps, fibroids or some vaginal infections may be accompanied by brown discharge.
Brown discharge and period
Menstruation is the most common time for this type of discharge to appear. It can appear before, during and after menstruation, and in most cases it is due to physiological processes:
- Before menstruation: a brownish discharge a day or two before menstruation is usually a warning that the endometrium is beginning to shed.
- During menstruation: lighter bleeding days are common.
- After menstruation: the uterus sometimes expels small traces of retained blood in the following days, which appear as a dark brown discharge.
If this discharge continues for more than two or three days after menstruation, especially if it is accompanied by discomfort, it is advisable to consult a specialist..
Brown discharge and pregnancy
Any change in discharge during pregnancy is usually a cause for concern, especially if it involves blood. However, brown discharge is not always a cause for alarm.
In the first weeks of pregnancy, a brownish discharge may appear as a result of implantation bleeding, i.e. when the embryo attaches to the endometrium. It is also common for the cervix, which is more sensitive due to the increased blood supply, to bleed slightly after an examination or sexual intercourse, causing brown spotting.
In most cases this is benign and temporary, but if the discharge is accompanied by intense abdominal pain, heavy bleeding or general discomfort, it is important to consult a doctor. These symptoms may be the first sign of complications such as miscarriage or ectopic pregnancy.
Later, in the second or third trimester, brown discharge may be related to the expulsion of the mucus plug, a warning that labour is approaching. In some cases, however, it may indicate problems with the placenta, requiring urgent medical assessment.
What to do if brown discharge appears?
In most cases, this is a normal phenomenon of the cycle or pregnancy. Even so, it is advisable to observe it and record when it appears, its duration and associated symptoms (pain, bad smell, fever).
This data is very useful for the specialist in identifying the cause and determining whether any intervention is needed.
Dr. Cristina Guix
Fertility expert gynaecologist in Barcelona IVF
