If you’ve experienced a period (menstruation), you’re likely familiar with the signs and symptoms that accompany it. The most obvious symptom of your period is bleeding through the vagina and abdominal cramps. But most of the signature symptoms that characterize periods actually start in the week or two leading up to it.
There are many changes in the body that happen as your body prepares for your period. These changes are driven by menstrual phase hormones released by your pituitary gland and gonads (ovaries). To understand what is happening in your body before and during your period, it’s helpful to understand your menstrual cycle as a whole.
Your Period Is the First Phase of Your Menstrual Cycle
Once you enter your reproductive years, you’ll experience monthly periods (unless you’re pregnant, breastfeeding, or entered menopause). The medical term for your period is menstruation. Menstruation is one of four cycles your body goes through in order to prepare for the possibility of pregnancy.
The entire cycle is called the menstruation cycle and takes an average of 28 days. However, many women experience shorter cycles (around 21 days) and some women experience longer cycles (up to 35 days).
The four menstrual cycle phases are:
- Menstruation (~Day 1-7): The uterine lining and unfertilized egg shed through the vagina. This is more commonly known as your period.
- Follicular Phase (~Day 1-13): Hormones stimulate the ovaries to produce a cluster of follicles that sit on the surface of the ovary, each containing an immature egg. Your uterine lining thickens in preparation for a possible pregnancy.
- Ovulation (~Day14-16): One of the follicles from the previous phase ruptures to release a mature egg into the fallopian tube. This is the phase when you’re most fertile.
- Luteal Phase (~Day 17-28): The ruptured follicle evolves into the corpus luteum, a structure that releases progesterone to maintain the uterine lining.
- If pregnancy doesn’t occur, the corpus luteum withers and dies. As progesterone levels drop, the uterine lining breaks down and prepares to be shed.
- If pregnancy does occur, the menstrual cycle is disrupted and menstruation won’t occur.
Hormonal changes dictate the transition from one phase to the next and. They trigger the changes in your body that cause you to experience a variety of signs and symptoms throughout each phase. The main reproductive hormones are:
- Luteinizing Hormone (LH)
- Follicle Stimulating Hormone (FSH)
- Human Chorionic Gonadotropin (if fertilization occurs)
A drop in progesterone and estrogen cause some of the most dramatic signs and symptoms you experience during your menstrual phase.
Menstrual Phase vs Menstrual Cycle
Before we dive into what happens during your menstrual phase, it’s important to understand that your menstrual period is distinctly different. Your period is the 5-7 days you have your period every month. It is NOT the same as your menstrual cycle.
Your menstrual cycle is the entire monthly cycle that your body goes through to prepare for the possibility of pregnancy.
Your menstrual period is the first phase of that menstrual cycle. It’s often referred to as the first phase because it starts on day 1.
The Menstrual Phase
The first day of the menstrual phase signals the start of your menstrual cycle. The menstrual phase happens in the uterus and lasts approximately 5-7 days. During this time, your levels of estrogen and progesterone drop drastically, which causes your uterus to shed its lining from the previous month’s menstrual cycle through your vagina. The unfertilized egg is also shed.
This phase will only happen if the egg from the previous menstrual cycle was not fertilized and pregnancy doesn’t occur. Shedding your uterine lining (endometrium) allows your body to start over the process of preparing for pregnancy.
While the menstrual phase is happening in the uterus, the follicular phase is happening in your ovaries. The follicular phase also starts on day 1 but extends all the way until ovulation, at around day 14. There are no recognizable symptoms associated with this phase.
Common Symptoms of Periods
The sudden drop in female sex hormones (estrogen and progesterone) causes certain physical and emotional symptoms. Some women may feel these very intensely while others may barely notice them at all. The severity of these symptoms may also fluctuate month-to-month, so don’t be alarmed if you feel different from one month to the next. And some months, you may not even notice any symptoms at all!
During your menstrual phase, you may experience all or none of the following.
- Abdominal cramps
- Breast tenderness
- Bloating or fluid retention
- Lower back pain
- Diarrhea or constipation
- Low energy, fatigue
- Cravings for specific foods
- Mood swings
- Trouble sleeping
You will likely start feeling many of these symptoms a week or two before your period during the late luteal phase. They often act as an ‘alert’ to let you know your period is coming. When you feel these symptoms before your period begins, it’s known as premenstrual syndrome (PMS).
The ABC’s of Premenstrual Syndrome (PMS)
The phase just before menstruation is called the luteal phase. During this time, a structure called the corpus luteum withers and dies. This structure releases progesterone so, as it shrinks, progesterone levels start to drop.
Since the uterine wall needs progesterone to maintain itself, it will also start to break down. These changes cause you to feel PMS, which includes many of the same signs and symptoms of menstruation that are mentioned above including abdominal cramps, mood swings, and bloating.
If you experience PMS (premenstrual syndrome), don’t fret, It’s extremely common and nothing to be concerned about (despite how uncomfortable it may feel). According to the Journal of Reproductive Medicine, over 90% of women experience PMS symptoms.
PMS is defined as a collection of physical and emotional symptoms that can last until a few days into menstruation, which includes cramps.
In rare cases, PMS cramps symptoms are extreme to the point that they regularly interfere with daily life. If this is the case, you should visit your doctor for some medical advice on potential treatments.
How to Treat the Symptoms of Periods
If you experience PMS symptoms before and/or during your period, you’re very familiar with how uncomfortable it can be. Luckily, there are some things you can do to alleviate the pain, as recommended by Planned Parenthood.
- Exercise, meditation, and/or yoga
- A warm bath
- Heating pad for your stomach or lower back
- Over-the-counter pain relievers like Ibuprofen can help with cramps
- Acupuncture or acupressure
- A healthy diet rich in iron and calcium and low in sugar, salt, and caffeine
- Hormonal birth control (like the birth control pill)
What Does It Mean If You Miss a Period?
The signs and symptoms characteristic of PMS signal your period is about to start. But what if that doesn’t happen?
The signs and symptoms of early pregnancy are actually quite similar to the symptoms of PMS. It’s important to know the subtle differences between pregnancy symptoms and PMS symptoms. Some unique signs of early pregnancy include:
- You are very late or miss a period
- Milky white vaginal discharge
- Darkening of the areola and nipple area
If you suspect you’re pregnant you should always visit your doctor.
Other reasons you may miss or stop having periods are:
- Stress & anxiety
- Diet & eating disorders
- Polycystic ovary syndrome (PCOS)
- Uterine fibroids or polyps
- Birth control & other medications
When to Seek Medical Advice
If your PMS and period symptoms, including cramps, are so extreme that they prevent you from functioning in your daily life, it’s time to visit your doctor.
Extreme PMS symptoms are actually a sign of something called premenstrual dysphoric disorder. The Mayo Clinic describes PMDD as a severe, sometimes disabling extension of premenstrual syndrome (PMS). If this sounds familiar to you, don’t panic. See your doctor immediately as they will be able to recommend some treatments that can help.