Overview
Looking for a straightforward way to ease menstrual cramps? You're not alone. Over 80% of people who menstruate experience painful period cramps at some point in their lives.1 While we have little control over the arrival of our unwelcome monthly visitor, we can try to manage the pain it brings. In the long-standing realm of natural solutions, heat therapy offers a drug-free, non-invasive approach to pain relief that’s suitable for most and works well alongside other strategies.2
By harnessing the tried and tested power of warmth, heat therapy helps to relax your muscles and enhance blood flow, taking the edge off painful period cramping so that you can get on with your day.2, 6, 9, 10, 11
Read on to discover the science, methods and evidence-based benefits of heat therapy for menstrual cramps to empower yourself in your menstrual health journey.
Understanding menstrual cramps
Causes
Before diving into heat therapy, let's first understand what causes menstrual cramps. During menstruation, the muscular wall of your womb (uterus) repeatedly contracts (tightens) and relaxes to shed its inner lining – the blood and tissue or ‘menstrual flow’ that leaves your vagina. These uterine muscle contractions can cause the blood vessels supplying the uterus to become pinched, reducing the blood flow – and therefore the oxygen (and nutrient) supply – to your uterus which results in painful cramping.3
Although the exact processes behind painful menstrual cramps aren’t fully understood, prostaglandins are thought to play a major role.3 During your period, these hormone-like chemicals are released from the uterine lining where they mediate uterine muscle contractions and contribute to pain and inflammation.4
The rise and fall of prostaglandin levels typically align with pain intensity before and during menstruation:
- 1 to 3 days before your period: Cramps may begin to arrive around this time as your body starts to produce more prostaglandins right before menstruation
- Around 24 hours of your period starting: Pain might be most severe here – this is usually when prostaglandin production hits its peak
- 2 to 3 days after the start of your period: Your cramps may finally start to ease off as prostaglandin levels subside with the shedding of the uterine lining 3
Higher levels or increased sensitivity to prostaglandins may partly explain why some people experience more painful cramping compared to others.5 Prostaglandins are also why non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen are effective at relieving menstrual pain in the majority (7 of 10) cases – these painkillers work by blocking prostaglandin production in your body. 3
Other factors such as hormonal imbalances and underlying health conditions can influence cramp severity. While mild to moderate discomfort is normal, some people experience cramps so painful that they interfere with daily activities. Painful cramps are known as dysmenorrhea, of which there are two types:
- Primary: Menstrual cramps that aren’t associated with a medical condition. This affects an estimated 45-95% of people who menstruate 3
- Secondary: Menstrual cramps arising from a medical condition that affects your reproductive organs e.g. endometriosis, uterine fibroids, adenomyosis, pelvic inflammatory disease (PID). This is less common compared to primary dysmenorrhea
In most cases, the pain lessens with age. Menstrual cramps may also become less painful after giving birth.
Common symptoms
The sensation of menstrual pain varies from person to person, but some ways it’s been described include:
- Throbbing
- Pressure
- Aching or tightening
- An intense stabbing pain
- A continuous, dull ache 1
Someone might experience none, one, or all of these types of pain at different times, on different days, and at varying intensities. They can also differ with each period in the same person. These pains usually affect the lower abdomen, back, and thighs, and may even radiate down the legs. 3
Additional symptoms often accompany menstrual cramps, including:
- Nausea
- Vomiting
- Diarrhoea or constipation
- Bloating
- Headaches
- Dizziness
- Sleep disturbances and daytime fatigue3, 6
Impact on daily life
Menstrual pain and related symptoms can disrupt various aspects of your life, including your concentration, personal relationships, social events and participation in sporting activities – and these are just the physical effects.6
The psychological effects of menstrual pain and the hormonal fluctuations orchestrating your menstrual cycle further compound its impact; increased stress and a worsening of mental health symptoms are frequently experienced in the days leading up to and during menstruation.7 It’s no wonder then, that period pain is the primary reason people who menstruate repeatedly miss days of school or work.3 Yet, research efforts into its prevention, and treatment surrounding the condition, are very lacking in proportion to the commonness of its occurrence.5
With the continued undervaluing and dismissal of period pain by many, from the likes of doctors through to those who endure the pain through gritted teeth accepting it as ‘normal’, access to easily implemented pain-relief methods such as heat therapy remains crucial.
How does heat therapy work?
Heat therapy, also known as thermotherapy, involves the application of heat (~40- 45°C) to the abdomen or lower back to alleviate pain and discomfort associated with menstrual cramps.2
Topically applied heat reduces the tension in your abdominal muscles and promotes vasodilation – or the widening of blood vessels. Relieving this muscle tension lessens the severity of uterine contractions, meaning less intense cramping. Meanwhile, enhanced blood flow helps to restore the circulation of fresh oxygen to the affected area, reducing tissue swelling and congestion which relieves the pressure being put upon the nerves in your abdominal region.2
How to use heat to reduce menstrual pain
Below are some ways that you can incorporate heat therapy into your toolkit for managing menstrual pain.
Hot water bottle or heating pad
One of the simplest ways to apply heat is by using a hot water bottle filled two-thirds of the way with hot (not boiling) water, or a heating pad set to a comfortable temperature. Place it on your abdomen or lower back for 15-20 minutes at a time, wrapped in a cloth or towel to prevent burns. If you choose to use a hot water bottle, avoid overfilling and be sure to gently squeeze the remaining air out before tightly securing its stopper to prevent leaks and bursting.
Warm bath
A warm bath can be both relaxing and therapeutic during menstruation. Soak in the warm water for 15-20 minutes, allowing the heat to soothe your muscles and help you unwind.8
Heat wraps or topical heat patches
Disposable heat wraps or patches are convenient options for on-the-go relief as they adhere to your clothing or skin and provide continuous heat for several hours. They're discreet, portable, and can be worn comfortably under clothing, allowing you to carry on with your day while experiencing relief from menstrual cramps. Remember to check the manufacturer’s instructions for proper use.2
Electric blanket
For slightly more prolonged comfort, consider using an electric blanket at a low to medium temperature to keep your body warm and relaxed. This method might be particularly helpful for those having trouble falling asleep due to persistent cramps – although it’s not recommended to leave these on overnight without thermostatic control. It’s always important to stick to relevant safety guidelines when using this approach.
Benefits of heat therapy for menstrual cramps
Scientific research so far recognises heat therapy as a valuable tool for easing menstrual discomfort.2, 3, 9, 10 In fact, some research even shows that it may be as effective as ibuprofen and more effective than paracetamol at alleviating pain.5, 11 It’s worth noting, however, that studies investigating heat therapy for menstrual cramps are limited and often based on small populations of people with primary dysmenorrhea – further, more rigorous, trials are needed to establish more concrete and widely applicable evidence.2
Nonetheless, heat therapy has a compelling set of benefits:
- Natural pain relief: Heat therapy offers a natural aid alongside or as a side-effect-free alternative to painkillers - when used correctly. This may be especially useful to those who can’t take NSAIDs (e.g., people with stomach ulcers)
- Convenience and accessibility: Heat therapy can be easily and continuously incorporated into your daily routine, whether at home, work or on the go
- Cost-effective: Compared to medications or other treatments, heat therapy is relatively inexpensive and can be implemented with readily available household items2
Safety considerations and precautions
While heat therapy is generally safe and well-tolerated, it's essential to use caution and follow safety guidelines.
- Making your heat source safe: Avoid applying heat directly to the skin to prevent burns. Always wrap the heat source in a padded cover, cloth or towel
- Duration and frequency: Prolonged or repeated use of concentrated heat sources (like hot water bottles) can result in a skin rash known as erythema ab igne. Limit heat therapy sessions to 15-20 minutes at a time to avoid overheating or skin irritation12
- Who shouldn’t use heat therapy? If you have diabetes, poor circulation, or sensory impairments, consult your healthcare provider before using heat therapy
If your menstrual cramps are severe, persistent, getting suddenly or progressively worse, or accompanied by other concerning symptoms, seek medical advice for proper evaluation and management. While menstrual pain itself doesn’t cause medical complications, underlying conditions can, if left unaddressed.13
Summary
Heat therapy offers a simple, effective, and natural solution for alleviating menstrual cramps. With benefits including muscle relaxation and improved blood circulation, heat therapy may provide a simple, convenient and painkiller-free approach to enhancing overall well-being during your menstrual cycle with minimal risk. Whether you prefer a hot water bottle, heat wraps or a warm bath, there's likely a heat therapy method suited to your preference and lifestyle – all of which are most effective when you're mindful of your safety during their use. While further research is valuable, current evidence supports the use of heat therapy as a practical and accessible means of pain relief, helping you to focus on living your life to the fullest.
References
- Grandi G, Ferrari S, Xholli A, Cannoletta M, Palma F, Romani C, et al. Prevalence of menstrual pain in young women: what is dysmenorrhea? J Pain Res. 2012; 5:169–74. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3392715/.
- Jo J, Lee SH. Heat therapy for primary dysmenorrhea: A systematic review and meta-analysis of its effects on pain relief and quality of life. Sci Rep. 2018; 8:16252. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6214933/.
- Itani R, Soubra L, Karout S, Rahme D, Karout L, Khojah HMJ. Primary Dysmenorrhea: Pathophysiology, Diagnosis, and Treatment Updates. Korean J Fam Med. 2022; 43(2):101–8. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8943241/.
- Ricciotti E, FitzGerald GA. Prostaglandins and Inflammation. Arterioscler Thromb Vasc Biol. 2011; 31(5):986–1000. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081099/.
- Iacovides S, Avidon I, Baker FC. What we know about primary dysmenorrhea today: a critical review. Hum Reprod Update. 2015; 21(6):762–78. Available from: https://academic.oup.com/humupd/article-lookup/doi/10.1093/humupd/dmv039.
- Guimarães I, Póvoa AM. Primary Dysmenorrhea: Assessment and Treatment. Rev Bras Ginecol Obstet. 2020; 42(8):501–7. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10309238/.
- Handy AB, Greenfield SF, Yonkers KA, Payne LA. Psychiatric Symptoms Across the Menstrual Cycle in Adult Women: A Comprehensive Review. Harv Rev Psychiatry. 2022; 30(2):100–17. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8906247/.
- Goto Y, Hayasaka S, Kurihara S, Nakamura Y. Physical and Mental Effects of Bathing: A Randomized Intervention Study. Evid Based Complement Alternat Med. 2018; 2018:9521086. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6011066/.
- Armour M, Smith CA, Steel KA, Macmillan F. The effectiveness of self-care and lifestyle interventions in primary dysmenorrhea: a systematic review and meta-analysis. BMC Complement Altern Med. 2019; 19:22. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6337810/.
- Burnett M, Lemyre M. No. 345-Primary Dysmenorrhea Consensus Guideline. Journal of Obstetrics and Gynaecology Canada. 2017; 39(7):585–95. Available from: https://linkinghub.elsevier.com/retrieve/pii/S1701216316399303.
- Latthe PM, Champaneria R. Dysmenorrhoea. BMJ Clin Evid. 2011; 2011:0813. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275141/.
- Kettelhut EA, Traylor J, Sathe NC, Roach JP. Erythema Ab Igne. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2024. Available from: http://www.ncbi.nlm.nih.gov/books/NBK538250/.
- Nagy H, Carlson K, Khan MA. Dysmenorrhea. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2024. Available from: http://www.ncbi.nlm.nih.gov/books/NBK560834/.