How do you know if the sadness and discouragement you feel are normal or if it's depression? While it's normal to feel blue occasionally, depression isn't something that will just go away. It can cause harm to your life and relationships and shouldn't be ignored.

Check out these seven warning signs:

1. Deep sadness

We are all sad and discouraged from time to time. Often we wish we could stay in bed and not go to work. But intense and frequent periods of sadness can lead to depression. With that depressive sadness comes sobbing, isolation, hopelessness and the feeling of loneliness.

2. Sleep disorders

Because of the anxiety that often accompanies depression, it is common for a person to have insomnia. And when sleep does finally come, it's often restless and unrefreshing, which makes you tired in the daytime.

Another disorder commonly associated with depression is hypersomnia, which is the opposite of insomnia. It's a condition where the person finds it difficult to stay awake during the day and get excessive sleep at night.

3. Negative thoughts

"Life sucks!","People don't like me," "I can't do it!", "I'm a failure!","There's no use trying.", "I'm ugly/fat/clumsy!","It would be better if I were dead.","I can't trust anyone!","I'm going to kill myself!" These are all examples of the types of negative thoughts that accompany depression. Those who are depressed lose belief in themselves, others and in life.

4. Disinterest and apathy

If you lose interest in people, sex, working, having fun, or life in general, you likely have depression.

5. Low self-esteem

Low self-esteem generates anxiety, fear and depression. A person with a low self-esteem doesn't consider himself or herself to match up to those around him either physically or intellectually.

Studies show those who are obese are 25 percent more likely to have depression than those who are not. Those who are underweight are also more likely to suffer from depression.

6. Laziness in getting ready

A person with depression often loses pleasure in things like getting dressed, taking a shower or being beautiful.

7. Physical pain

In addition to deep sadness, depression manifests itself physically through various types of pain. Experts say that some people who are depressed become more sensitive to pain. The most common symptoms are:

• Abdominal pain and gastrointestinal discomfort, including disorders such as gastritis and irritable bowel syndrome (among others).

• Headaches.

• Pain caused by muscle tension especially in the neck, shoulders and back.

• Pain and tightness in the chest.

• A sensation of having something stuck in the throat.

If you have any of the symptoms listed above, seek a professional (such as a psychologist or psychiatrist) urgently for an accurate diagnosis. Depression is a serious, yet often silent, illness. If left untreated, the damage to your health, family, social and professional life will be even greater. It can even lead to death.

This article has been adapted and translated from the original, "7 sinais que mostram que você tem depressão," which was published on familia.com.br.