Feeling upset but don’t know why? There might be an underlying cause, such as hormonal changes, past trauma, depression, or stress.

If you find yourself feeling low or crying without an obvious reason, you might wonder what’s going on. This is often nothing to worry about — you might just be feeling extra sensitive today.

In some cases, there may be a cause you haven’t thought of yet.

Feeling sad is a natural part of life. In fact, sadness has some benefits, like helping us process difficult events and connect with others. But that doesn’t always make it easier in the moment.

However you feel today, know that you’re not alone and there are many ways to find joy again.

People feel sad for lots of reasons — but it’s also possible to feel sad for no reason that you can think of.

Sometimes, a seemingly small disappointment can affect you more than you think, leaving you upset long afterward. You might not connect your current sadness to what happened. Feeling lonely, experiencing rejection, and having relationship issues can all have a major and lasting effect on how you feel.

Even a lack of sleep or feeling hungry can put you in a sour mood some days.

In other cases, there might be a deeper cause. Factors like depression, trauma, grief, and hormonal changes can affect your mood without your conscious awareness for years, yet they may affect your emotions every day.

Consider setting time aside to sit with your emotions and work out what’s causing them. You may not find the answer, and that’s OK — but sometimes, finding and naming the cause can help you accept your feelings and move toward happiness.

Below, we look at some reasons you might be feeling sad and tips for boosting your mood.

Depression, also called major depressive disorder (MDD) or clinical depression, is characterized by a low mood and loss of interest in things you usually enjoy that lasts for at least 2 weeks.

Depression is one of the most common mental health conditions. The National Institute of Mental Health (NIMH) reports that about 8.4% of adults in the United States have experienced depression.

Other symptoms of depression include:

If you think you have depression but aren’t sure if it’s MDD, you might want to read about other types of depression, too.

A type of depression called persistent depressive disorder (PDD), or dysthymia, is depression that lasts for 2 years or more. People who experience it might not remember a time when they didn’t feel sad.

If you only feel sad for seemingly no reason during a specific part of the year, it could be a type of depression called seasonal affective disorder (SAD) or depression with seasonal features. SAD is more common during the fall and winter when days are shorter.

Trauma is an emotional or physical response to one or more harmful or life threatening events or circumstances with lasting adverse effects on your mental and physical well-being, according to the Substance Abuse and Mental Health Services Administration (SAMSHA).

Trauma can affect your brain and nervous system, and many people experience emotional dysregulation long after the traumatic situation is over.

Emotional dysregulation can look like this:

  • quick mood shifts
  • feeling sad or crying for no obvious reason
  • being easily overwhelmed
  • finding it very difficult to calm down or self-soothe

If you find yourself affected by a traumatic event long after it ends — such as intrusive memories or avoiding situations that remind you of the trauma — you may be living with post-traumatic stress disorder (PTSD) or complex PTSD.

Changes in your reproductive hormone levels can cause mood changes, including feeling down or upset.

In those cases, you might be unable to figure out why you’re sad because hormonal changes happen without conscious awareness.

Various mood-altering issues that stem from shifting reproductive hormone levels include:

  • Premenstrual dysphoric disorder (PMDD). People with PMDD experience depression a week or so before their period starts, along with other mood changes.
  • Postpartum depression. Hormonal levels fluctuate during and after pregnancy. This can result in postpartum depression.
  • Perimenopause. This is the transitional period before menopause. Many hormonal shifts happen at this time, including mood shifts.

When your depression symptoms have a hormonal cause, they may ease when your hormone levels readjust, but sometimes they can linger. It’s often worth speaking with a mental health professional to help support you through these periods.

Sometimes you’ll feel sad when you’re dealing with a specific problem in your life. High levels of stress can lead to emotional dysregulation and unpredictable mood shifts in anyone. In fact, stress can have both mental and physical effects.

Stressful or upsetting situations might include:

  • moving house
  • work stress
  • problems at work
  • relationship conflict
  • breaking up with a partner or losing a friend
  • a sick loved one or pet

Once you adjust to the change or cope with the situation, the feelings will likely go away. If you are having trouble adjusting to the situation consider speaking with a mental health professional.

When you feel sad, various methods can offer relief and help you find joy again.

  • Physical activity. Staying active releases feel-good endorphins to lift your mood. You can read about the mental health benefits of exercise here.
  • Listen to music. Music can sometimes offer comfort or energize you when you’re feeling sad. Music can affect your hormone levels in ways that can improve your mood, relieve anxiety, and reduce stress.
  • Practice self-compassion. Being gentle and patient with yourself can help. Practicing self-compassion has many benefits, like boosting self-esteem and easing depression.
  • Spend time outside. Spending time in nature or green spaces can boost your mood. Research says it may ease depression symptoms by reducing cortisol (stress hormone) levels in your blood.

Sometimes people feel sad for no obvious reason, and that’s OK. The feelings often pass.

If you feel sad often, find it hard to deal with your mood, or think you have a mental health condition it can help to speak with a mental health professional. A primary care doctor can be a good first step, too.

Want to learn more about starting therapy? Psych Central’s How to Find Mental Health Support resource can help.

If you feel suicidal, you can reach out to the National Suicide Prevention Lifeline. There are helpful resources on their website, or you can call the hotline at 1-800-273-8255. Remember that this feeling won’t last forever, and you can get help to overcome the experience.