If you are wondering whether your daughter's or son's teenage mood swings are normal, the short answer is usually yes: ups and downs are a regular part of puberty, driven by changing hormones, a brain that is still being rebuilt, too little sleep and a lot of social pressure. What matters most is not how loud the mood is but how long it lasts, how deep it goes and whether it gets in the way of school, friends and home life. Staying calm, listening before fixing and keeping a few clear rules help in most families, and a doctor or therapist is worth calling when low or irritable moods last for weeks.
In brief:
- Mood swings are common in puberty and usually ease as teens get older.
- Hormones, brain changes, poor sleep and stress all play a part.
- Stay calm, listen first and talk again once things have cooled down.
- Look at duration, severity and impact: weeks of low mood need a professional.
- Sleep, routines and a few clear rules calm many days.
In this article · 10 min read
Puberty brings physical, social, mental and emotional changes all at once. Kids Helpline explains that hormones affect not only the body but also the brain, and that the parts of the brain that regulate emotions and decisions are often the last to mature (Kids Helpline). So a teen can feel perfectly fine at breakfast and flooded by anger or sadness an hour later, without being able to say why. That is stressful for them and for you, and it helps to remember that the storm is rarely about you.
Why teenage mood swings happen
There is rarely one cause. The usual ingredients are:
- Hormones. Sex hormones released during puberty influence both the body and the way a teen feels.
- A brain under construction. Kids Helpline notes that the areas for managing emotions and making decisions develop late. Teens feel strongly before they have all the tools to handle it.
- Sleep. Lack of sleep is on the same list of triggers, and a tired teen is usually a more irritable one.
- Stress and pressure. School demands, peer pressure, family conflict, anxiety and feeling self-conscious all add up (Kids Helpline).
- Body changes. Periods, growth spurts and a new body can make a teen feel unsure of themselves. Our guide to a first period kit shows how a little preparation takes some of that stress away.
What is normal, and what to look at more closely
A study published in Child Development followed 474 adolescents from age 13 to 18, who rated their moods every day for happiness, anger, sadness and anxiety. The swings were biggest in early adolescence and became steadier as the teens grew older. Girls reported more intense swings in happiness and sadness than boys, but both stabilized at a similar pace. Anxiety was different: it rose early, dipped, then rose again towards the end of the teen years (Maciejewski and colleagues, Child Development, 2015; summary by NPR). The lead researcher's advice for parents was to worry when a teen does not show that normal decline, for example a 16- or 17-year-old whose swings are getting stronger instead of weaker.
The table below puts the usual picture next to the signs that deserve a closer look. It is a guide, not a diagnosis.
| Usually part of puberty | Look closer if... |
|---|---|
| Quick changes within a day, often linked to tiredness, hunger or a conflict | The low or irritable mood lasts for more than two weeks |
| Slammed doors and sharp words, followed by calm and sometimes an apology | There is a big change in behaviour, feelings or thinking that is not like your teen |
| Wanting more privacy and time with friends | Withdrawal from friends and family, or from things they used to enjoy |
| Being tired and moody on school days | Sleep or appetite change a lot and stay changed |
| Swings that slowly become less frequent over the years | Swings that get stronger over time, or affect school, friendships and home |
Kids Helpline names three things to watch: duration (more than two weeks), severity (significant changes in behaviour, feelings and thoughts) and impact (effects at home, at school and with friends). MedlinePlus gives the same two-week guideline: if low feelings last two weeks or longer, talk to your teen's health care provider (MedlinePlus, 2024).
How often does a low mood last that long? In the Youth Risk Behavior Survey of the Centers for Disease Control and Prevention (CDC), a large school survey, 40% of high school students said that in the past year they had felt so sad or hopeless almost every day for two weeks or more in a row that they stopped doing some usual activities. The figure was 53% for girls and 28% for boys (CDC, YRBS Data Summary & Trends Report 2013–2023, 2024). These answers describe a hard stretch, not a diagnosis, but they show why the two-week rule matters and why girls and boys both deserve to be asked how they really are.
How to respond to teenage mood swings: 6 steps
- Stay calm first. Kids Helpline suggests staying calm, listening and acknowledging how your teen feels. Take a breath before you answer. Your calm is contagious, and so is your stress.
- Choose your moment. In the middle of an outburst, nothing sinks in. Say "I can see you're upset, let's talk when you're ready" and come back to the topic later, once things have settled. A short walk, a snack or some music often opens the door better than a question.
- Listen before you fix. The researcher behind the study above recommends listening openly to your teen's feelings and offering solutions or other views only if they are open to them. Try "That sounds really hard" instead of "You're overreacting".
- Keep the rules, soften the tone. Clear boundaries still matter. Kids Helpline suggests keeping rules and expectations while giving your teen space to process feelings and helping them solve problems rather than solving everything for them.
- Protect sleep and routines. A regular bedtime, screens put away for the last hour of the day and a calm evening make the next morning easier. Our guide to phone rules for teens has ideas for doing that together.
- Notice the good moments. Kids Helpline also suggests praising good behaviour, especially during the "up" times. A simple "I liked how you handled that" tells your teen that you see more than the bad days.
What to say, what to skip
| Try saying | Better to skip |
|---|---|
| "I can see this is hard. Do you want to talk or have some space?" | "Calm down!" |
| "I'm here when you're ready." | "You're being dramatic." |
| "I felt hurt when the door slammed. Can we talk later?" | "You always do this." |
| "What would help right now?" | "When I was your age..." |
"I feel" sentences keep the focus on what you experience instead of attacking your teen, and they can help a talk stay calm.
Keep a two-week check
If you are unsure, write a few lines for two weeks: how your teen slept, what their mood was like in general and whether it stopped them from doing normal things such as school, seeing friends or eating. You are not spying; you are collecting facts. If most days show a low, irritable or empty mood, or things get worse, that note will help a doctor or counsellor understand what is happening. Friendship problems can also drive moods up and down, so our guide on how to tell if a friend is toxic may help you and your daughter or son talk it through.
In this short video from the Geisinger health system, counsellor Priscilla Riley explains how normal teenage moodiness differs from the signs of depression, and which changes deserve a check-in:
Understanding teenage moodiness and depression (Geisinger)
Where the book fits
100 Mysteries of Puberty for Girls by Magda Pabst is written to the teen herself, in a warm and slightly playful tone. Besides mood swings, it covers stress and anxiety (organization, breathing, less caffeine and screen time, more sleep), sleep itself, how to ask for help and how to talk with parents using "I feel" statements. It also explains in simple terms how the teen brain changes, which can make the whole thing feel less mysterious.
Magda Pabst's view
In 100 Mysteries of Puberty for Girls, Magda Pabst starts from a reassuring point: mood swings are normal, because the brain is reorganising and hormones are busy. She then gives girls a short toolkit they can use on their own: notice the feeling and accept it without judging yourself, talk to someone, do something you enjoy, move (even a walk counts), get outside into nature, and stay connected with friends and family. Her nuance is one many parents need to hear too: time alone is fine and can help a girl understand what she feels, as long as it does not turn into shutting everyone out. A closed bedroom door is not automatically a warning sign; days of withdrawal from everyone are.
Books Go Publications has sold over 100,000 copies of its guides, mainly across the United States, Germany, France and Spain, and each language edition of this book went through a native-speaker editor so that its warm tone survives the translation.
This is a book to hand to your daughter, not a replacement for a conversation with her, and it is not medical advice. It does not diagnose anything, and it says clearly that anxiety or low mood that gets overwhelming is a reason to see a therapist. Some chapters speak frankly about sexuality and relationships, so you may want to read it first.
When to ask a professional
Call your family doctor, a paediatrician or a mental health professional if:
- sadness, irritability or emptiness lasts more than two weeks;
- your teen pulls away from friends, family or activities they used to enjoy;
- sleep, appetite or school results change a lot and stay changed;
- you see signs of self-harm, risky behaviour, or substance use;
- your teen talks about not wanting to be alive.
Trust your instinct: if you are worried, it is better to ask early. If you or your teen need to talk to someone right now, the international directory findahelpline.com lists free helplines by country. In an emergency, contact your local emergency services immediately. You can also start with other Books Go Publications blog guides, and find more books on the Books Go Publications home page.
Who it is for
This guide is for anyone who lives or works with a teenager whose moods go up and down.
- Parents of a preteen: read it before the storms begin, so the first slammed door feels expected rather than alarming.
- Parents of a moody teen: use the six steps and the two-week check to stay calm and to know when a low mood needs a professional.
- Teens themselves: the section on causes shows that hormones, sleep and a changing brain are behind many swings, which makes them feel less strange.
- Grandparents, teachers and coaches: the phrases to try and to skip work just as well outside the family home.
Key terms
- Puberty: the years in which a child's body matures into an adult body, driven by sex hormones.
- Hormones: chemical messengers carried in the blood; in puberty they also influence how a teen feels.
- Mood swing: a quick change from one emotion to another, often stronger than the situation seems to explain.
- Persistent sadness: feeling sad or hopeless almost every day for two weeks or more, a reason to talk to a doctor.
- Depression: a health condition with lasting low mood or loss of interest, which only a doctor or therapist can diagnose.
- "I feel" statement: a sentence that describes your own feeling ("I felt hurt when...") instead of blaming the other person.
Frequently asked questions
Are teenage mood swings normal?
Yes, they are common during puberty and usually ease with age. Hormones, a developing brain, stress and tiredness all play a part. They become a concern when they last for weeks, feel very intense or disrupt school, friendships and family life.
How long do teenage mood swings last?
They tend to be strongest in early adolescence and then settle gradually through the teen years (Child Development study, 2015). There is no exact timetable, because every teen is different.
Why is my teenager so angry all the time?
Anger is often a way to let off steam about stress, tiredness, pressure from friends or changes in the body. If anger is constant, very intense or comes with withdrawal, bad sleep or low mood, talk to a doctor.
Do girls have stronger mood swings than boys?
In the study above, girls reported more intense swings in happiness and sadness, but boys and girls became steadier at a similar pace. Boys have mood swings too, and they deserve the same patience.
How can I tell mood swings from depression?
Look at duration, severity and impact. Low mood or irritability for more than two weeks, big changes in behaviour or thinking, and trouble at school, with friends or at home are reasons to speak to a professional. Only a doctor or therapist can diagnose.
What can I do in the middle of an argument?
Keep your voice low, say you want to understand, and offer to continue the conversation when you both feel calmer. Come back to it later, when the intensity has gone down.
Sources
- Mood swings and puberty, Kids Helpline
- Young teens suffer most from turbulent mood swings, NPR (2015), on a study in Child Development
- Recognizing teen depression, MedlinePlus (reviewed 2024)
- Maciejewski D. F. et al., A 5-year longitudinal study on mood variability across adolescence using daily diaries, Child Development (2015)
- Youth Risk Behavior Survey Data Summary & Trends Report 2013–2023, Centers for Disease Control and Prevention (2024)
This article is for general information only and does not replace advice from a doctor, dietitian or other qualified professional.
