Medical Guide to Menstrual Pain: Complete Analysis of Causes, Diagnosis & Scientific Treatment

Introduction

Menstrual pain (Dysmenorrhea) affects 70-90% of women of reproductive age globally, with 10-15% experiencing severe pain that significantly impacts daily life and work. As an important component of women's reproductive health, menstrual pain is not merely a physiological phenomenon to "endure and get through," but a medical condition requiring scientific understanding, accurate diagnosis, and effective management.

This guide provides an in-depth medical analysis of the pathophysiological mechanisms of menstrual pain, detailed classification of 10 major causes, professional diagnostic methods, and guidance on when to seek medical help. It aims to help women develop scientific understanding of menstrual pain and achieve precise health management.

What is Menstrual Pain? Medical Definition of Symptoms

Core Symptom Characteristics

The core symptom of menstrual pain is cyclical lower abdominal pain occurring during menstruation. From a medical perspective, this pain has the following characteristics:

• Pain Nature: Cramping, colicky, or persistent dull pain
• Pain Location: Primarily in the lower abdomen, may radiate to lower back and inner thighs
• Timing: Closely related to menstrual cycle, usually appearing before or during menstruation
• Duration: Ranging from hours to days

Associated Symptom Spectrum

Menstrual pain is often accompanied by the following systemic symptoms:

Gastrointestinal Symptoms:

• Nausea and vomiting
• Diarrhea or constipation
• Loss of appetite

Neurological Symptoms:

• Headache and dizziness
• Fatigue and weakness
• Difficulty concentrating

Endocrine-Related Symptoms:

• Breast tenderness
• Mood swings and irritability
• Edema

Pain Severity Classification

Based on the impact of pain on daily life, menstrual pain can be classified as:

• Mild: Minor pain, no impact on daily activities
• Moderate: Noticeable pain, mild impact on daily activities, may require pain medication
• Severe: Intense pain, severely affects daily activities, requires bed rest or sick leave

Medical Classification and Cause Analysis of Menstrual Pain

Primary Dysmenorrhea: Pain Caused by Physiological Mechanisms

Primary dysmenorrhea refers to functional menstrual pain without organic pathology, accounting for 80-90% of menstrual pain cases. Main mechanisms include:

Cause 1: Excessive Prostaglandin Secretion

Pathogenesis:

• Endometrial shedding during menstruation releases large amounts of prostaglandin F2α (PGF2α)
• PGF2α causes intense uterine smooth muscle contractions
• Uterine vascular constriction leads to local ischemia
• Prostaglandins enter blood circulation causing systemic symptoms

Clinical Features:

• Pain appears synchronously with menstruation
• Mostly cramping pain
• Often accompanied by nausea, vomiting, diarrhea

Cause 2: Abnormal Uterine Muscle Contractions

Pathogenesis:

• Increased uterine muscle sensitivity to prostaglandins
• Abnormal frequency and intensity of uterine contractions
• Narrow cervical canal in adolescents increases contraction resistance

Clinical Features:

• Pain severity not completely correlated with prostaglandin levels
• May be accompanied by abnormal menstrual flow

Cause 3: Vasopressin Influence

Pathogenesis:

• Elevated vasopressin levels
• Synergistic action with prostaglandins enhances uterine contractions
• Affects uterine blood flow perfusion

Clinical Features:

• Pain may begin before menstruation
• Often accompanied by water-sodium retention symptoms

Secondary Dysmenorrhea: Pain Caused by Organic Diseases

Secondary dysmenorrhea is caused by pelvic organic diseases, accounting for 10-20% of menstrual pain cases, but the proportion increases with age.

Cause 4: Endometriosis

Disease Mechanism:

• Functional endometrial tissue implanted outside the uterine cavity
• Ectopic endometrium bleeds with menstrual cycles
• Causes local inflammation, adhesions, and cyst formation

Clinical Features:

• Progressive worsening menstrual pain
• Deep dyspareunia
• May be associated with infertility
• Pain may persist after menstruation

Cause 5: Adenomyosis

Disease Mechanism:

• Endometrial glands and stroma invade the uterine muscle layer
• Ectopic endometrium bleeding in muscle layer causes thickening
• Uterine volume increases, abnormal contractions

Clinical Features:

• Diffuse lower abdominal pain
• Increased menstrual flow and prolonged periods
• Uniform uterine enlargement

Cause 6: Uterine Fibroids

Disease Mechanism:

• Benign smooth muscle tumors of the uterus
• Affect uterine contraction patterns
• Compress surrounding tissues and blood vessels

Clinical Features:

• Pain severity related to fibroid location and size
• Submucosal fibroids have most obvious symptoms
• Often accompanied by increased menstrual flow

Cause 7: Pelvic Inflammatory Disease (PID)

Disease Mechanism:

• Upper reproductive tract infection and inflammation
• Chronic inflammation leads to adhesion formation
• Pain worsens during pelvic congestion

Clinical Features:

• Persistent pelvic pain
• May be accompanied by fever and abnormal discharge
• Dyspareunia and dysuria

Cause 8: Intrauterine Device Related

Disease Mechanism:

• Copper ions cause aseptic inflammation
• Increase prostaglandin release
• Foreign body stimulates uterine contractions

Clinical Features:

• Worsened menstrual pain after IUD insertion
• Menstrual flow may increase
• Pain related to IUD type

Cause 9: Pelvic Adhesions

Disease Mechanism:

• Sequelae of surgery, infection, or endometriosis
• Fibrous band formation limits organ mobility
• Menstrual pelvic congestion pulls adhesive bands

Clinical Features:

• Relatively fixed pain location
• May be accompanied by intestinal symptoms
• Position changes may affect pain

Cause 10: Reproductive Tract Malformations

Disease Mechanism:

• Congenital or acquired structural abnormalities
• Affect menstrual blood outflow
• Increase uterine contraction resistance

Clinical Features:

• Severe menstrual pain immediately after menarche
• May be accompanied by menstrual abnormalities
• Requires imaging examination for diagnosis

Differential Diagnosis of Menstrual Pain

Differentiation from Other Abdominal Pain

Accurate differentiation of menstrual pain from other causes of abdominal pain is crucial for correct diagnosis:

Menstrual Pain vs Early Pregnancy Cramping vs Labor Contractions

Timing Characteristics:

• Menstrual Pain: Related to menstrual cycle, cyclical occurrence
• Early Pregnancy Cramping: After missed period, irregular
• Labor Contractions: Full-term pregnancy, highly regular

Pain Nature:

• Menstrual Pain: Cramping or dull pain, mainly lower abdomen
• Early Pregnancy Cramping: Mild pulling sensation, similar to mild menstrual pain
• Labor Contractions: Intense contraction feeling, entire uterus tightening

Associated Symptoms:

• Menstrual Pain: Nausea, vomiting, diarrhea and other menstrual-related symptoms
• Early Pregnancy Cramping: Early pregnancy symptoms, beware of ectopic pregnancy if bleeding occurs
• Labor Contractions: Bloody show, water breaking and other labor signs

Duration:

• Menstrual Pain: Hours to days, relief after menstruation
• Early Pregnancy Cramping: Intermittent and brief episodes
• Labor Contractions: Progressively longer with shorter intervals

Differentiation Between Primary and Secondary Dysmenorrhea

Age of Onset:

• Primary Dysmenorrhea: 1-2 years after menarche
• Secondary Dysmenorrhea: After puberty, especially after age 30 or childbirth

Pain Pattern:

• Primary Dysmenorrhea: Synchronous with menstruation, appears hours before or after menstruation begins
• Secondary Dysmenorrhea: May start 1-2 weeks before menstruation, longer duration

Pain Nature:

• Primary Dysmenorrhea: Cramping colicky pain, mainly concentrated in lower abdomen
• Secondary Dysmenorrhea: Varied pain types, may involve wide pelvic areas

Pain Trend:

• Primary Dysmenorrhea: May decrease with age or after childbirth
• Secondary Dysmenorrhea: Progressively worsens over time

Associated Symptoms:

• Primary Dysmenorrhea: Mainly nausea, vomiting, diarrhea and other systemic symptoms
• Secondary Dysmenorrhea: Besides systemic symptoms, often has heavy menstrual flow, dyspareunia, infertility and other gynecological-specific symptoms

Physical Examination Findings:

• Primary Dysmenorrhea: Gynecological examination usually normal
• Secondary Dysmenorrhea: May find uterine enlargement, tenderness, nodules and other signs of organic pathology

Pain Assessment and Recording Methods

Standardized Pain Assessment

Visual Analog Scale (VAS)

• 0 points: No pain
• 1-3 points: Mild pain, no impact on daily activities
• 4-6 points: Moderate pain, affects daily activities
• 7-10 points: Severe pain, seriously affects quality of life

Functional Impact Assessment

Assess pain's impact on:

• Sleep quality
• Work/study efficiency
• Social activity participation
• Exercise capacity
• Emotional state

Establishing a Menstrual Pain Diary

Recommend recording the following information:

• Menstrual cycle dates
• Pain onset time and duration
• Pain intensity scores
• Pain nature description
• Associated symptoms
• Relief methods used and their effectiveness
• Impact on daily life

When to Seek Medical Help

Emergency Medical Indications

The following situations require immediate medical attention:

• Sudden severe abdominal pain with nausea and vomiting
• Pain with fever (>38.5°C)
• Heavy vaginal bleeding
• Pain with fainting or shock symptoms
• Suspected ectopic pregnancy (missed period + abdominal pain + vaginal bleeding)

Elective Medical Indications

The following situations warrant timely medical evaluation:

• Newly occurring menstrual pain or change in nature
• Progressively worsening pain
• Ineffective regular pain medication
• Severe impact on daily life and work
• Abnormal vaginal discharge
• Painful intercourse or defecation/urination
• Known or suspected pelvic disease
• Infertility with menstrual pain

Medical Examination Items

Doctors may perform the following examinations:

Basic Examinations:

• Detailed medical history
• Gynecological examination
• Pelvic ultrasound

Further Examinations:

• Complete blood count, inflammatory markers
• Tumor marker testing
• Pelvic MRI
• Hysteroscopy or laparoscopy

Conclusion: Scientific Understanding, Precise Management

As a common gynecological symptom, menstrual pain involves complex and diverse pathophysiological mechanisms. Correctly distinguishing between primary and secondary dysmenorrhea and accurately identifying situations requiring medical intervention are important components of women's health management.

By establishing scientific understanding of menstrual pain, using standardized pain assessment methods, and seeking professional medical help in a timely manner, women can effectively manage menstrual pain symptoms and improve quality of life. Remember, menstrual pain is not a "female destiny" that must be endured, but a health issue that can be effectively managed through scientific methods.

Important Reminder: This guide is for health education reference only and cannot replace professional medical diagnosis and treatment. If you have menstrual pain concerns, please consult a gynecologist promptly for personalized diagnosis and treatment plans.