What is the difference between normal menstrual pain (primary dysmenorrhea) and pathological menstrual pain (secondary dysmenorrhea)?

Menstrual pain is known as dysmenorrhea and is a common experience for more than half of women, with many experiencing mild pain for a day or two each month. However, for some women, this pain can be severe and hinder daily activities. Dysmenorrhea is classified into two main types: primary and secondary, each with different causes and characteristics.

Primary Dysmenorrhea (Normal Pain)

Primary dysmenorrhea is the most common type of menstrual pain; it is cramping pain that occurs before or during menstruation and is not caused by another medical condition. These pains usually begin shortly after a girl starts menstruating. Primary dysmenorrhea pain is caused by natural chemicals called prostaglandins, which are produced in the lining of the uterus. These chemicals cause the uterine muscles and blood vessels to contract. Prostaglandin levels are highest on the first day of the period and decrease as bleeding continues and the uterine lining sheds, which explains why the pain tends to ease after the first few days of the menstrual cycle [1].

For many women, periods become less painful as they age, and this pain may also improve after childbirth [1].

Secondary Dysmenorrhea (Pathological Pain)

Secondary dysmenorrhea is defined as menstrual pain resulting from a disorder in the reproductive organs. This pain often starts at a later age, worsens over time, and usually lasts longer than normal menstrual cramps. For example, the pain may begin a few days before the period starts, increase as it continues, and may not disappear even after it ends [1].

Some conditions that can cause secondary dysmenorrhea include:

• Endometriosis: This condition occurs when tissue similar to the uterine lining grows in other areas of the body, such as the ovaries, fallopian tubes, behind the uterus, and the bladder. This tissue breaks down and bleeds in response to hormonal changes, causing pain, especially around the time of menstruation. Scars called adhesions may form inside the pelvis, which can cause organs to stick together and cause pain [1].
• Fibroids: These are tumors that form on the outer surface, inside, or in the walls of the uterus. Fibroids located in the uterine wall may cause pain, whereas small fibroids usually do not [1].
• Adenomyosis: This condition develops when the tissue that usually lines the uterus begins to grow into the muscular wall of the uterus. This condition is more common in older women who have had children [1].
• Problems in the uterus, fallopian tubes, or other reproductive organs: Some congenital defects that a woman is born with can lead to pain during menstruation [1].
• Other medical conditions: Certain medical conditions like Crohn's disease and urinary disorders can worsen during the menstrual cycle and cause pain [1].

When Should You Consult a Doctor?

It is important to consult an obstetrician-gynecologist if you suffer from severe or unusual menstrual pain. Symptoms and your menstrual cycle should be discussed with the doctor. The doctor may recommend a pelvic exam, and medication may be the first step in treatment [1]. If medications do not relieve the pain, the focus should be on finding the underlying cause of the pain [1].

It is advised to see a doctor in the following cases [2]:

• If over-the-counter pain relievers and home remedies do not help, and the pain interferes with your daily life.
• If the cramps suddenly worsen.
• If you are over 25 and have severe cramps for the first time.
• If you have a fever along with menstrual pain.
• If the pain is persistent even when you are not on your period.

For more information on menstrual pain, you can visit Menstrual pain: When is it normal and when does it require medical consultation? (Arabic)

Diagnosis and Treatment

To diagnose the cause of severe menstrual pain, the doctor may ask about your medical history and perform a pelvic exam. An ultrasound or other imaging test may also be recommended [2]. In some cases, an obstetrician-gynecologist may recommend a laparoscopy, a procedure that allows the doctor to view the pelvic organs [1].

Treatment options depend on the type and cause of the dysmenorrhea. For primary dysmenorrhea, the first step is often medication, such as nonsteroidal anti-inflammatory drugs (NSAIDs), which reduce prostaglandin production [1]. Hormonal contraceptives, such as birth control pills, patches, vaginal rings, or hormonal IUDs, can also be used to relieve pain [1].

If the pain is caused by secondary dysmenorrhea, treatment focuses on addressing the underlying condition causing the pain. This may include medication, or in some cases, surgery to remove fibroids or endometriosis tissue [1].

Medical references

• Dysmenorrhea: Painful Periods
• Period Pain