Is it bad to miss a period for 3 or 4 months at a time?

Last updated on October 23, 2020


Is there a web site that you could direct me to in order to ask health questions? My friend in the last year missed her period for 3 to 4 months at a time, then it comes back, then she goes without one for 3 or 4 months again. She did this when she was younger as well (she is 18 now). Back then it was a month and a half or so, and now in the last year, it’s doing it for 3 or 4 months.

A second thing is her father and she throws up every morning when brushing their teeth. They both throw up unwillingly every morning when they have to brush their teeth. I was wondering if it is cause and effect. She says it’s not voluntary and she found out her father does it too. I would usually call it an eating disorder, but I actually believe her on this one. At the same time, I can see a connection to a lack of digesting food not getting the food that is needed, and not eating all day because of being at work which could cause her cycle to be off and make it not happen as often due to lack of nutrition. I would say she has an eating disorder, but she wants to eat when I am around her. She suggests eating half the time. I will be with her for 10 hours and she doesn’t go to the bathroom usually and when she does it’s a minute or less. I looked for the signs but I’m kind of lost. I don’t know if it’s all by chance or if it is an eating disorder. I was wondering about your opinion. She is about 120 pounds.


I don’t have one particular medical site that I go to for answers. There are several good one available and I rate them more by the quality of the organization behind the site.

Generally, go for the easiest answer first. Missed menstrual periods are most likely caused by not eating enough. Even athletes, who are in great shape, have to watch for this because they are using so many calories in their performance. There have been studies on women athletes that show that a few months in a row with no periods trigger a loss in bone strength. Whether this extends to non-athletes without periods is currently not known. But a loss in bone strength can be permanent, so it is not worth the risk.

Periods are often irregular during adolescence, but by this time she should be more regular. She should make sure she eats regular, healthy meals and fruits for snacks. If she can’t get her periods regular, she needs to see a gynecologist.

If your friend has a habit of brushing her teeth after meals, it might not be the brushing that is the trigger, but the meal itself. People with stomach ulcers tend to vomit after a meal — especially the morning meal. She and her dad might be assuming that the vomiting is from the last thing they did instead of a cause that takes a short while to build up. Some medications also have this side-effect. By the way, brushing is a known trigger for vomiting if the stomach is already upset.

Here are Cleveland Clinic‘s suggestions:

When trying to control nausea:

  • Drink clear or ice-cold drinks.
  • Eat light, bland foods (such as saltine crackers or plain bread).
  • Avoid fried, greasy, or sweet foods.
  • Eat slowly and eat smaller, more frequent meals.
  • Do not mix hot and cold foods.
  • Drink beverages slowly.
  • Avoid activity after eating.
  • Avoid brushing your teeth after eating.
  • Choose foods from all the food groups as you can tolerate them to get adequate nutrition.

Another concern is that people who vomit tend to get dehydrated, which then makes them more likely to be nauseous. She can improve her health greatly by simply making sure she drinks lots of liquids during the day. People who take medications that leave them dehydrated (in the morning having dry mouth and a hard time swallowing) recommend using Biotene toothpaste and Biotene mouthwash which are specifically designed for this problem. They find that they don’t get nauseous when using them.

There is a simple measure for whether you are getting enough liquids. Your urine should be a light yellow color. A dark color means you aren’t drinking enough fluids.