What causes menstrual pain?
Painful menstruation, or dysmenorrhea, (dys·men·or·rhea) is a common condition affecting 45-95% of people who get periods. Many people believe pain during menstruation is normal, leaving many cases unreported and untreated. Sometimes underlying issues, such as endometriosis, cause the pain - this is called secondary dysmenorrhea. Primary dysmenorrhea, on the other hand, is menstrual pain/cramping without any underlying pelvic disorders.
So, what causes primary dysmenorrhea? Studies show people with dysmenorrhea produce more hormone-like substances, called prostaglandins, that lower pain thresholds (meaning the person feels pain more easily) and cause more frequent and uncoordinated uterine muscle contractions, leading to decreased blood flow in the uterine muscle, and ultimately, pain. Prostaglandin levels are especially high in the first 48 hours of one’s period.
Other studies have found that people with dysmenorrhea have more pro-inflammatory cytokines - substances that promote inflammation throughout the body - than those without dysmenorrhea, but it is unclear how this might exactly cause painful menstruation. Other studies suggest people with dysmenorrhea are more sensitive to pain in general, but consensus on this is inconsistent.⁴
Potential risk factors
Although scientists need more research to fully understand what makes someone more likely to develop menstrual pain, some studies suggest the following possible culprits⁴:
- Beginning menstruation at an earlier age
- Heavier/longer-lasting periods
- Being overweight
- Drinking alcohol
- Family history of dysmenorrhea
- Having never given birth (nulliparity)
Chronic Pain and Dysmenorrhea
Another explanation for primary dysmenorrhea could have more to do with the brain than with the uterus. When someone feels pain for 3 to 4 months, without anyunderlying medical cause, pain may become more intense or show up when the original cause for pain is no longer there.
With chronic pain, our nervous system gets upregulated, picking up normal sensations within and to our body as dangerous. Now the brain gets barraged with multiple danger signals, so over time the brain behaves like a helicopter parent. It sends a huge amount of pain signals to protect the body, even though there isn’t further physical damage happening to our body.⁵ This is not a good thing! It means our brain could make us feel pain even in response to something that shouldn’t hurt at all! This process is called central sensitization. During menstruation, central sensitization may cause the brain cells, called neurons to process sensation in and around the uterus to go haywire and exacerbate pain!
New scientific research has found that multiple parts of the brain process the many ways that we sense pain. These different parts of the brain then work together to start, maintain and, good news, can also reverse chronic pain. It’s a complex system that is connected to emotions, muscles, hormones and movement! Thankfully your physical therapist has got your back and is here to help! Physical therapists can use this understanding of pain science and their expertise of the neuromuscular system to design specific physical therapy interventions that work with your individual experience of dysmenorrhea.
How Can Physical Therapy Help?
Three physical therapy techniques that may help to alleviate menstrual pain:
Exercise, Manual techniques, and Electrotherapy
- Designing and supervising and progressing unique Therapeutic Exercise programs
- Isometric Exercise
How would PT be different from exercising on my own in the gym?
- Your Physical Therapist incorporates evidence based research and a physical therapy evaluation of your movement ability and muscular strength to individualize your exercise program, finding the right types frequency and progressions of exercise to help lower your discomfort and symptoms. ³
2. Manual Techniques
Manual techniques can also be effective in relieving dysmenorrhea in some women. Physical therapy manual techniques, such as Neuromuscular Manual Therapy (NMT), may influence new sensation patterns and help with pain relief by building new neuron pathways. NMT also stimulates endorphin release in the body. Endorphins are a type of brain chemical or neurotransmitter that our brains produce naturally, that is known to relieve pain. Together, all these great effects of NMT are all thought to bring short and long term pain relief, if you are experiencing dysmenorrhea.¹
Some of these techniques include direct strokes applied by the physical therapist using their hands in parts of the patient’s abdomen, diaphragm. Low back and groin area (sacroiliac ligament, sacrotuberous ligament, iliopsoas, piriform, and quadratus lumborum). Some of the techniques that PT uses start with light massage at the surface and then deeper direct strokes with lengthways and sideways stroke and some pinching techniques to relieve pain.¹
TENS (Transcutaneous Electrical Nerve Stimulation)
Modalities such as high frequency TENS (transcutaneous electrical nerve stimulation) may also help with short term pain relief in conjunction with other medical therapy or in some cases has been shown to help in isolation.² These are small adhesive pads that apply small electrical stimulation to your skin and underlying muscles. TENS can be part of your physical therapy session in addition to manual techniques and therapeutic exercise. Just another tool that can be used to help reduce primary dysmenorrhea, so hooray for that!
Now that you are empowered with information and know that periods should not cause pain, you can speak with your physical therapist to learn more about how therapy could help! Yay!
- Barassi G, Bellomo RG, Porreca A, Di Felice PA, Prosperi L, Saggini R. Somato-Visceral Effects in the Treatment of Dysmenorrhea: Neuromuscular Manual Therapy and Standard Pharmacological Treatment. The Journal of Alternative and Complementary Medicine. 2018;24(3):291-299. doi:1089/acm.2017.0182.
- Burnett M, Lemyre M. No. 345-Primary Dysmenorrhea Consensus Guideline. Journal of Obstetrics and Gynaecology Canada. 2017;39(7):585-595. doi:1016/j.jogc.2016.12.023.
- Carroquino-Garcia P, Jiménez-Rejano JJ, Medrano-Sanchez E, de la casa-Almeida M, Diaz-Mohedo E, Suarez-Serano C. Therapeutic Exercise in the Treatment of Primary Dysmenorrhea: A Systematic Review and Meta Analysis. Phys Ther. 2019;99(10):1371-1380. http://eds.a.ebscohost.com/eds/pdfviewer/pdfviewer?vid=2&sid=622ff009-5da2-4dbb-bd6d-223dc552090b%40sdc-v-sessmgr01. Accessed November 15, 2019.
- Iacovides S, Avidon I, Baker FC. What we know about primary dysmenorrhea today: a critical review. Human Reproduction Update. 2015;21(6):762-778. doi:1093/humupd/dmv039.
- McAllister MJ. What is Central Sensitization? Understanding Chronic Pain. Institute of Chronic Pain. May 2017. https://www.instituteforchronicpain.org/understanding-chronic-pain/what-is-chronic-pain/central-sensitization.