The common factors of it are related to lifestyle, such as stress, body weight, and smoking status.
[1] Several studies indicate that COVID-19 vaccine of any type may disrupt the menstrual cycle, although only momentarily.
Lengths ranging between eight and 20 days are considered moderately irregular.
[10] However, other studies suggest that it can take anywhere between 2[11] and 7[12][13][14] years to establish regularity after an individual's first menses.
Other types of conditions that can be referred to by "irregular menstruation" include: