The most common reason for visiting clinics in the world is headache, which occurs in all age groups (Alshimmery et al., 2009). Headache accounts for 1 to 2% of visits to the emergency department and up to 4% of visits to doctors offices (BR M. Harrisons, 2012). Headaches are caused by tension, displacement, inflammation, vascular spasm, or expansion of pain-sensitive structures in the head and neck (Burch, 2019). The etiology diagnosis of headache requires un-derstanding its pathology, preparing a history, and spe-cifying the characteristics of pain as acute, subacute, or chronic by performing a detailed physical examination and summarizing differential diagnoses (Eigenbrodt et al., 2021; Goadsby et al., 2021). In most cases, the cause of the headache is benign. 

However, a new headache can be the main symptom or the first manifestation of a systemic disease or dan-gerous intracranial disease (Ha H, Gonzalez, 2019). So, a systematic and comprehensive clinical evaluation is required. Migraine is defined as a common headache that is usually one-sided, mainly has a throbbing qua-lity, and is often accompanied by nausea, phono-phobia, and photophobia (Iannone et al., 2022). Migr-aine headaches affect more than 10% of the popu-lation. Two-thirds to three-quarters of migraine cases occur in women, and more than 90% occur before the age of 40. The family history of migraine can be traced mainly (Neumeier et al., 2021; Papetti et al., 2021). Although little is known about the molecular mecha-nism of migraine, studies suggest that calcitonin gene-related peptide (CGRP) is released and activated by a variety of stimuli through stimulation of ion channels known as TRP. It can intensify migraine attacks (Robbins MS, 2021). A diet that helps to control weight gain can positively affect the severity of mig-raine (Ruschel and De Jesus, 2022). Migraine is clini-cally divided into three categories: classic migraine or with aura that occurs after the occurrence of aura (tran-sient visual, sensory, or motor symptoms and disor-ders), common migraine or without aura, and chronic migraine that has changed to a frequent headache syn-drome after a long time (Saylor et al., 2018; Silberstein et al., 2018). 

Due to the importance and frequency of migraine headaches, this study investigated the epidemiological characteristics and prevalence of symptoms in migra-ine patients and compared the identified pattern with the pattern recorded in other parts of the world. 

This study was conducted on 90 patients referred to Walfajr Health Center and Shahid Beheshti Hospital in Shiraz in 2013 and 2014. The sample was selected by convenience sampling (referring to the mentioned places during the study, the researcher took a sample from the referring people. If the selected people were not included in the samples for any reason, they were replaced by the next person). This cross-sectional study was conducted using the descriptive-analytical method. The statistical population included all the pati-ents referred to the mentioned medical centers with all age and gender ranges. New patients or patients dia-gnosed with migraine was visited by a neurologist and their symptoms were recorded. The gender, age range, and headache symptoms of the patients were collected and documented through questionnaires. 

Statistical Analysis 

The data were analyzed using descriptive statistics and paired t-test and Chi-square statistical tests. A P-value less than 0.05 were considered significant level. SPSS software was used to analyze the data.

Questions and Hypotheses 

The study was conducted to answer and test the following four questions and hypotheses: 

1) Is migraine more common in women? 

2) Is migraine more common before the age of 40? 

3) Are the clinical symptoms of the patients the same as in the reference books?

4) Is migraine without aura more common than mig-raine with aura? 

Findings Fig.1 to 3 shows the results of gender frequ-ency, age range, duration, aura, and clinical symptoms of migraine patients. As can be seen, 85.6% of patients were female and 14.4% were male (Fig. 1a). The age range of the patients was normally distributed. Most of the patients (45.6%) were 30 to 40 years old, and the lowest frequency (1.1%) belonged to the age range of 1 to 10 years (Fig. 1b). 

Fig. 1: The frequency of gender (a) and age range (b) in migraine patients.

In terms of migraine duration, most patients (52.2%) experienced 4 to 24 hours, and the lowest frequency (4.4%) belonged to more than 72 hours (Fig. 2a). Mig-raine was without aura in the majority of patients (65.6%) (Fig. 2b). Moreover, among the clinical sym-ptoms of migraine, including one-sidedness or two-sidedness, throbbing, nausea, phonophobia, photoph-obia, recovery with rest, and exacerbation with move-ment, the highest frequency belonged to throbbing, phonophobia, and photophobia, respectively, and two-sidedness and exacerbation with movement were less common (Fig. 3).

Fig. 2: The frequency of duration (a) and aura (b) in migraine patients.

Fig. 3: The frequency of clinical symptoms in migraine patients.

The results of the chi-square test suggested that migr-aine was more common in females, the clinical symp-toms of the patients in this study were the same as the reference book and the global pattern, and migraine without aura was more common than migraine with aura (P-value was smaller than 0.05 in all three cases). So, Hypotheses 1, 3, and 4 were confirmed. Further-more, by setting the test value to 35, the results of the one-sample t-test indicated that migraine was more common before the age of 40 (P<0.05, 95% confidence interval between -31.23 and -30.80). In this way, Hypo- thesis 2 was confirmed. 

In a study by Al Shimmery et al. (2009) on 200 patients from Iraqi Kurdistan in 2007 and 2008, the pattern of migraine headaches and the effect of age and duration of the disease on the symptoms were investi-gated (Simon et al., 2009). Most of the studied cases (77%) were females. The mean age of onset was 22.33 ± 9.52 years (± SD), and the most common type of migraine observed was without aura (72%). In this study, various symptoms such as phonophobia (92%), nausea (86.5%), photophobia (84%), dizziness (78%), scalp thinning (75%), pallor (64%), sweating (57%), vomiting (50%), arm pain (39%), and chest pain (6%) were investigated concerning the age of onset and duration of the disease. The duration of the disease was not significantly correlated with the age of onset and spread of migraine symptoms. Besides, there was no significant correlation between the duration of the disease and the frequency of attacks. It is concluded that many symptoms of migraine are the same in each attack regardless of the duration of the disease and the age of onset, except for the tendency to vomit, which may be less common in younger patients. The findings showed that the prevalence and symptoms of migraine are almost similar between the population of patients in this study and other parts of the world despite cultural, social, and nutritional differences, etc., indi-cating that these differences probably have not much effect on the prevalence of migraine and its epide-miological characteristics. It can be concluded that the headache is likely to be benign and there is no definite need for imaging if the patient has a headache with migraine characteristics. Patients should know the clinical symptoms of migraine so that they dont get anxious when visiting the doctor. Similar studies are recommended to be conducted in other provinces of Iran to confirm what was mentioned about the pattern and characteristics of migraine epidemiology. It is also recommended to investigate the prevalence of types of auras in migraine so that patients can better understand their symptoms and predict headache attacks. 

We are grateful to all the Dear Professors for providing their information regarding this research. 

The authors of this manuscript declare their agreement with the statements. Authors also state separately that they have all read the manuscript and have no conflicts of interest.