Hi,
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Severe dysmenorrhea associated with vomiting and dehydration is not normal. It should not be ignored if it is affecting your personal and work-life. Consider visiting your doctor/gynecologist at the earliest for further evaluation to rule out serious underlying causes like endometriosis, pelvic adhesions, PID, adenomyosis, ovarian cysts etc. You might need to have laparoscopic examination done to confirm and treat conditions like endometriosis, pelvic adhesion, ovarian cysts, etc. Treatment as appropriate (based on examination findings and investigations results) would be started to help you control your symptoms. If you are taking antispasmodics for relief of abdominal cramps, you should take it as soon as your start with periods (preferable on the expected period date) and the cramps instead of allowing the intensity of the cramps to increase. Take adequate rest. Drink plenty of water. Be in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately.
Take care.