The main difference between spotting and a period is the quantity of blood. Period blood, even when light, is usually more consistent and lasts several days.
Spotting does not usually point to a serious medical issue. Noting the timing of the spotting, how long it lasts, and other relevant details, however, can help determine what’s causing it.
Some periods begin or end with spotting, and some women bleed more lightly than others. As such, it can be hard to tell the difference.
Spotting is any bleeding from the vagina that is not due to a woman’s monthly period.
Some women also refer to the light bleeding before and after a period as spotting.
Some women track their cycles and know what is normal for their bodies, which means they can usually tell the difference between spotting and regular bleeding.
Menstrual bleeding occurs roughly every 28 days in non-pregnant women. Each month, the uterine lining thickens to prepare for pregnancy. If a woman does not get pregnant, the uterus sheds its lining, causing a monthly period.
Some traits of menstrual bleeding include:
- A regular schedule: While the length of time between periods varies among women, most women experience periods around the same time each month.
- A predictable bleeding pattern: Every woman’s menstrual bleeding follows its own pattern. For many women, a monthly period begins with light spotting, gets heavier for a day or two, and then gets gradually lighter, ending with spotting.
- Time spent not bleeding: Some women with hormonal imbalances or health issues may spot throughout the month. Periods usually last 5-7 days, and never last an entire month.
- Menstrual bleeding is often accompanied by other symptoms: In the week or so before a period, changes in hormones can trigger symptoms, such as breast tenderness and headaches. As the uterus contracts to expel the uterine lining as blood, some women experience cramping that can range from mild to intense.
- Menstrual blood is usually red: The color can help differentiate a period from spotting, although the blood may be brown at the beginning or end of the period. Some women see large clots or strings of blood with their monthly period, which is less common with spotting.
A range of factors can cause spotting, and every woman’s pattern of spotting may be slightly different.
Some characteristics of spotting include:
- Irregular timing: Women may spot for a day, stop bleeding, and start again. Some women experience spotting intermittently throughout the month.
- Associated with predictable menstrual cycle events: Unexplained spotting is often irregular. But spotting can also occur alongside ovulation. Some women experience a day or two of light spotting every month.
- May be associated with injuries or other symptoms: This includes abdominal pain.
- Often a different color from a woman’s normal menstrual period: Some women spot brown blood. Others find that the blood from spotting is lighter, a different texture, or smells odd.
- May be related to hormonal birth control medication: Starting on new hormonal birth control might change the amount and timing of bleeding.
Spotting does not always mean something is wrong. Some of the most common reasons women experience spotting include:
When the ovaries release an egg at ovulation, a tiny follicle ruptures to allow the egg out. In some women, this causes light spotting that lasts for a day. There might be a sudden lower right or left twinge a few days before as ovulation occurs.
Ovulation spotting takes place in the middle of the cycle and is never heavy. Rarely, it may be accompanied by light cramping that may last from a few hours to one day.
Uterine fibroids or polyps
Uterine fibroids and polyps are noncancerous growths in the uterus. They can grow quite large, however, and may cause pain and other symptoms.
Many women with fibroids or polyps experience irregular bleeding between periods. Certain types of spotting can also signal the presence of these uterine growths. This includes spotting that lasts across several cycles, or that is accompanied by:
- pelvic pain
- fertility difficulties
- irregular periods
About a week after a sperm fertilizes an egg, the egg must implant in the uterus. Sometimes this causes light bleeding known as implantation bleeding.
The bleeding typically only lasts a day or two and occurs around a week after ovulation. This usually takes place about a week or two before a woman’s period is due.
Hormonal contraceptives, including birth control pills and hormonal shots and implants, can cause spotting. Spotting is especially common in the first few months, as the body’s hormones adjust to contraceptives.
Spotting may change over time, occur intermittently, or follow a predictable pattern. If spotting begins several months after starting contraceptives, with no previous spotting, it may point to an underlying problem and the woman should visit her doctor.
Breast-feeding suppresses ovulation, particularly if the baby is exclusively breast-fed. It is important to know that ovulation will occur about 2 weeks before the first period, so it is possible to get pregnant while breast-feeding.
However, many women who are breast-feeding experience spotting. Hormonal shifts related to breast-feeding can cause spotting.
Hormonal changes that occur as the body prepares to ovulate for the first time after childbirth may also trigger spotting.
An injury to the vagina, cervix, or uterus may cause abnormal bleeding. Rough sexual intercourse or a PAP test, for example, can irritate the cervix or vaginal tissue and cause bleeding.
If the bleeding is minor and not accompanied by pain, it’s usually fine to see if it goes away. However, unexplained bleeding that is heavy or accompanied by pain can be a medical emergency.
About half of women who experience bleeding during pregnancy will have a miscarriage. In some cases, bleeding is the first sign that a woman is pregnant. Very early miscarriages may even be mistaken for unusually heavy menstrual periods.
Some sexually transmitted infections (STIs) can cause abnormal vaginal bleeding that looks like spotting. Gonorrhea is a common culprit, and may also cause unusual discharge or burning during urination.
Pelvic inflammatory disease (PID) is a type of chronic pelvic inflammation caused by an infection. Women with PID can experience infertility if symptoms go untreated. PID often causes spotting, particularly after intercourse. It can also cause pelvic pain.
Although rare, spotting may be a symptom of cancer. Types of cancer that can cause spotting include:
Spotting is often accompanied by pain and other symptoms and can last several months. Symptoms may get better and then worse, or get progressively worse.
Women who are past menopause or who have a family history of these cancers are at a heightened risk. It is never normal for postmenopausal women to experience vaginal bleeding.
Any woman who experiences prolonged spotting or new and unexplained spotting should go to the doctor. Women should contact a doctor immediately if:
- spotting is heavy, causes them to feel dizzy, or is accompanied by a foul odor
- they have recently experienced rape
- they believe the spotting could be due to an injury
- they are pregnant or could be pregnant
- they experience spotting after menopause
A woman should also see a doctor if the spotting:
- lasts more than a few days
- is accompanied by pain
- continues intermittently across more than one cycle
Sometimes women can adopt a wait-and-see approach. These circumstances include experiencing spotting that is:
- the same as spotting they have had before
- possibly due to implantation
- potentially due to ovulation
If women are unsure which of the circumstances described applies to their situation, then it is better to be cautious and contact a doctor for advice. In the majority of cases, however, spotting is not the sign of a medical condition and may only be temporary.