Weight loss is noticeable or fast
If clothes are suddenly looser, family members are noticing a change, or your teen is losing weight fast, it is reasonable to contact the doctor for advice.
Unexplained Weight Loss in a Child or Teen: When to See a Doctor
If your child or teenager is losing weight without trying, it can be hard to tell what is normal and what needs medical attention. Get clear, parent-friendly guidance on when weight loss may be a reason to call the doctor and what signs to watch for.
About 3–5 minutesPrivate assessmentNo long answers
About this assessment
Answer a few questions about the weight loss you’ve noticed
Share how much weight your child or teen has lost and any related changes, and we’ll provide personalized guidance on whether this sounds like something to monitor, schedule with a doctor, or discuss sooner.
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When weight loss may need medical attention
Children and teens can have growth changes, appetite shifts, and activity changes during puberty, but unexplained weight loss is worth paying attention to. If your child is losing weight without dieting, exercising more, or trying to slim down, it may be time to speak with a doctor. Weight loss that happens quickly, continues over time, or comes with other symptoms like poor appetite, stomach pain, fatigue, vomiting, diarrhea, fever, or mood changes should not be ignored.
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Signs it may be time to call the doctor
Your child is eating less or skipping meals
A child losing weight and not eating well may need medical evaluation, especially if appetite loss lasts more than a few days or keeps happening.
Other symptoms are happening too
Weight loss along with stomach issues, tiredness, frequent illness, excessive thirst, changes in mood, or trouble concentrating can point to an underlying health concern.
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Possible reasons for unexplained weight loss in puberty
Medical causes
Infections, digestive problems, thyroid issues, diabetes, and other health conditions can sometimes cause a child or teenager to lose weight without trying.
Appetite and eating changes
Stress, anxiety, depression, medication side effects, or an emerging eating disorder can affect how much a child eats and lead to weight loss.
Growth and lifestyle shifts
Puberty can change body shape and appetite, but ongoing or sudden weight loss without a clear reason is still something to discuss with a doctor.
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What parents can do next
Notice the pattern
Think about when the weight loss started, whether it has been gradual or sudden, and if there are changes in appetite, energy, sleep, or bathroom habits.
Look at the whole picture
Weight loss matters more when it comes with other symptoms or behavior changes. A doctor will want to know what else you have noticed at home.
Use a quick assessment for guidance
Answer a few questions to get personalized guidance on when to worry about weight loss in a child or teen and whether it may be time to seek medical help.
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Frequently asked questions
When should I worry about weight loss in my child?
You should be more concerned if the weight loss is noticeable, happens quickly, keeps going, or comes with symptoms like poor appetite, stomach pain, vomiting, diarrhea, fatigue, fever, or behavior changes. If your child is losing weight without trying, it is reasonable to call the doctor.
Should I call the doctor if my teenager is losing weight fast?
Yes. A teenager losing weight fast should be discussed with a doctor, especially if they are not trying to lose weight or if there are changes in eating, mood, energy, or physical symptoms.
Can puberty cause unexplained weight loss?
Puberty can bring changes in appetite, growth, and body shape, but unexplained weight loss should not automatically be assumed to be normal. If the change is significant, sudden, or paired with other symptoms, a doctor should evaluate it.
What if my child is losing weight and not eating much?
A child losing weight and not eating well may need medical attention. Causes can range from short-term illness to digestive issues, stress, depression, medication effects, or an eating disorder. If appetite loss lasts, keeps returning, or is affecting weight, contact the doctor.
What information will help when I talk to the doctor?
It helps to know about how much weight was lost, how quickly it happened, whether clothes fit differently, changes in appetite, stomach symptoms, energy level, mood, sleep, thirst, and any recent illness or stress. Our assessment can help you organize what you have noticed.
Personalized assessment
Get personalized guidance about your child’s unexplained weight loss
Answer a few questions about the amount of weight loss, eating changes, and related symptoms to better understand whether this may need routine follow-up or a sooner call to the doctor.