As parents, we’ve all been there—our once sweet, innocent child suddenly morphs into a moody, eye-rolling, door-slamming teenager, and we’re left wondering what on earth just happened.
Welcome to the turbulent world of adolescence, when hormones, social pressures, and emotional growth collide, leading to a rollercoaster of emotions and behaviors.
When their teen reaches adolescence, parents have to endure moments of uncertainty that can feel like walking through a dense forest. Red flags, however, can serve as our compass, guiding us toward early intervention and even professional help if necessary.

Here are some major warning signs that may indicate a problem in a teen.
- Drop in academic performance
- Excessive isolation
- Disruption in sleep patterns
- Lose interest in social activities or extracurricular activities once enjoyed
- Mood swings or excessive moodiness
- Irritability from time to time
- Aggressive behaviors
- Excessive anger
- Excessive risk-taking behaviors
- Unusual rebellious behavior
- Secretive behavior
- Avoidance behaviors
- Social isolation
- Extreme weight loss or dramatic weight gain
- A lack of personal hygiene
- Impulsive behavior
- Loss of appetite
- Feelings of worthlessness or hopelessness
- Covering up arms in the summer
- Excessive weight concerns
- Extreme dieting
- Delinquent behavior
- Risky sexual behavior
Associated Causes
Every warning sign can have a number of causes. Therefore, do not jump to conclusions after observing one behavior.
An isolated red flag might be a mere coincidence. Some behaviors may also be considered typical teen behavior. For instance, common mood swings are normal behavior, but extreme mood shifts are not.
Excessive red flag behaviors or multiple ones often indicate that the teen is grappling with issues or challenges.
Depression
Here are some common signs of depression in teens1.
- Excessive sleeping or insomnia
- Become uninterested in once enjoyable activities
- Appetite loss
- Lack of engagement with life
- Feelings of guilt or worthlessness
- Chronic low in mood
- Isolation from family members or stop spending time with friends
General anxiety disorder and other mental health disorders may show similar symptoms. Therefore, if you observe these behaviors, it is important to seek help from mental health professionals.

Self-harm
Self-injurious or self-destructive behavior is direct and deliberate bodily harm without suicidal intent. Self-injury typically involves cutting or carving the skin to decrease negative emotions or as a cry for help2.
Some common warning signs include
- Unexplained wounds or scars, often in patterns
- Hiding the skin, such as wearing long sleeves on a hot summer day
- Being alone in the bathroom or bedroom for a long period
- Sharp objects such as knives or razor blades hidden in possession
- Frequent accidental injuries
- Self-criticism
- Feelings of helplessness or hopelessness
Self-harm is one of the symptoms of mental illness, such as borderline personality disorder3.
It is also associated with adolescent sexual and physical abuse. Seek mental health counseling immediately if you notice these behaviors in your teen4.
Eating Disorder
Considerable weight loss is a common sign of eating disorders such as anorexia nervosa and bulimia nervosa.
Major signs of eating disorders are
- Obsessive weight measuring or calorie counting
- Patterns of weight loss
- Intense fear of gaining weight
- Negative body image
Many teenage girls are concerned about being overweight and may diet inappropriately. However, this is a common behavior for adolescents, and most do not have an eating disorder5.
Don’t hesitate to speak to your family health practitioner if you have any doubts.
Substance abuse
Youth abuse of drugs and alcohol is prevalent in the US, and most abuse begins during adolescence6.
Substance abuse and mental health conditions often co-occur.
The ability of parents to recognize these red flag signs is important so that early intervention for substance abuse can be sought.
- Red face, bloodshot eyes, or breath odors of alcohol7
- Lack of personal hygiene
- Irritability
- Extreme rage or mood swings
- In possession of illegal drug
- Difficulty focusing in school or completing assignments
- Secretive behavior, such as hiding in the bathroom or bedroom for long periods of time
- Signs of depression, bipolar disorder, or general anxiety disorder8
Also See: Coping Skills for Teens
References
- 1.Fava M, Kendler KS. Major Depressive Disorder. Neuron. Published online November 2000:335-341. doi:10.1016/s0896-6273(00)00112-4
- 2.Nock MK. Self-Injury. Annu Rev Clin Psychol. Published online March 1, 2010:339-363. doi:10.1146/annurev.clinpsy.121208.131258
- 3.Hodgson S. Cutting through the Silence: A Sociological Construction of Self-Injury. Sociological Inquiry. Published online May 2004:162-179. doi:10.1111/j.1475-682x.2004.00085.x
- 4.Hawton K, Saunders KE, O’Connor RC. Self-harm and suicide in adolescents. The Lancet. Published online June 2012:2373-2382. doi:10.1016/s0140-6736(12)60322-5
- 5.Rosen DS. Identification and Management of Eating Disorders in Children and Adolescents. Pediatrics. Published online December 1, 2010:1240-1253. doi:10.1542/peds.2010-2821
- 6.Burstein M. Use and Abuse of Alcohol and Illicit Drugs in US Adolescents. Arch Gen Psychiatry. Published online April 1, 2012:390. doi:10.1001/archgenpsychiatry.2011.1503
- 7.Saini G, Prabhat K, Gupta N. Drug addiction and periodontal diseases. J Indian Soc Periodontol. Published online 2013:587. doi:10.4103/0972-124x.119277
- 8.Simon NM. Generalized Anxiety Disorder and Psychiatric Comorbidities Such as Depression, Bipolar Disorder, and Substance Abuse. J Clin Psychiatry. Published online April 2009:10-14. doi:10.4088/jcp.s.7002.02