Primary dysmenorrhea constitutes a significant health, social and economic problems. It involves a broad spectrum of both physical and emotional manifestations with a prevalence that can reach 50 up to 91 % in young women . Furthermore, it compromises the most common gynaecological alternations and the major cause of women academic and work absenteeism which obviously reduces quality of life, daily activities and economic situation due to decreased working hours.

NSAIDs are the first therapeutic line for primary dysmenorrhea; however, they might be accompanied by some undesirable side effects, such as dyspepsia, headache and drowsiness .

Laser treatment is non-invasive, painless, and can be easily administered in primary care settings for a wide range of conditions. Laser treatment significantly reduces pain level in both acute and chronic painful conditions by increasing the production of endorphins.

Low intensity laser therapy (LTTT) as a physical therapy modality with variety of therapeutic effects. There are various researches concluded that it is a safe therapeutic modality for the treatment of dysmenorrhea .

More recently, the pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) , a form of high-intensity laser therapy (HILT), was introduced to the field of physical therapy. The use of pulsed Nd:YAG lasers with high peak powers (3kW) and wave length of 1064 nm has been increasing and is considered as a non painful and non invasive modality that can stimulate areas that can't be reached with the low power lasers with patients reporting more significant pain reduction . Studies have documented the anti-inflammatory, anti-edematous, and analgesic effects of Nd:YAG lasers, justifying their use in patients with pain issues .

In fact, the HILT program is effective and has a more prolonged effect in pain reduction, and improving QOL with effects lasting up to 12 weeks post-treatment .

There is limited literature regarding the clinical results of high intensity laser treatment for primary dysmenorrhea , this may be contributed to its high cost. So, this research is an attempt to add to the clinical knowledge in this field as it will investigate the difference between the effect of low and high intensity laser therapy on primary dysmenorrhea with the quality of life improvement being the main point of concern .

This study will be conducted on fifty two participants suffering from primary dysmenorrhea selected from Cairo Specialised Hospital( Department of Obestetrics and Gynaecology).

All females will be randomly divided into two equal groups:

• Group (A): lt will include 26 participants suffering from primary dysmenorrhea who will receive low intensity laser therapy 3 sessions per cycle for 3 consecutive cycles (one session will be applied the day before menstruation and the other two sessions on the 1st and 2nd days of menstruation).
• Group (B): It will include 26 participants suffering from primary dysmenorrhea who will receive high intensity laser therapy 3 sessions per cycle for 3 consecutive cycles (one session will be applied the day before menstruation and the other two sessions on the 1st and 2nd days of menstruation ).

All females will be given a full explanation of the study protocol and a consent form will be signed by each female before entry in this study

Inclusion Criteria:

- A)

• All females will be clinically diagnosed by gynaecologist with primary dysmenorrhea .
• Score ≥ 50 or moderate on Menstrual Distress questionnaire (MDQ)
• Their ages will range from 18-25 years old.
• Their BMI will be less than 30 kg/m² (El-Kosery et al., 2020).
• Being virgin.
• Having regular menstruation for the last 6 months (every 28-30 days with no intermittent bleeding).

Voluntary acceptance to participate in the study

Exclusion Criteria:

• Participants will be excluded if they have :

  • Systematic chronic diseases , adenomyosis, pelvic inflammatory disease.. etc
  • Mental disability .
  • Professional athletes (Jill et al., 2012).
  • Secondary dysmenorrhea pathology.
  • Menstrual irregularity.
  • Using hormonal contraception (such as contraceptives and injections) .
  • Epileptic fits .
  • Cardiac pacemakers.
  • Lumbar disc lesions .