So you've had a baby and, despite being knee-deep in diapers and functioning on very little sleep, the world is a brighter place. Just looking at your newborn's face brings you joy. Even though it is hard work, there is something wonderful about a having new baby in the family ...

Or maybe you don't feel quite this way. Maybe having a new baby is not the idyllic experience you expected. If so, you wouldn't be alone.

Ten percent of women experience postpartum depression (PPD). It can be mild and resolve with time or with therapy and support. But it can also be more severe, affecting a mother's relationship with her child and partner, her child's development, and her performance when she goes back to work.

Symptoms may start as early as within the first few weeks of giving birth — which is most common — or as late as a year after giving birth.

It can occur in women who have never had depressive symptoms before, but it is more common in women who have. Some women may have PPD with one pregnancy but not with a previous or with a subsequent pregnancy. However, if a woman does experience it, she has a higher than average risk of developing PPD again with the next pregnancy.

Postpartum depression is less of a taboo topic than it used to be, but it is easily unrecognized by mothers themselves, who are often overwhelmed and sleep-deprived simply by caring for the basic needs of their newborns. Or they may recognize their symptoms only in retrospect.

Actress Gwyneth Paltrow recently talked publicly about her struggle with postpartum depression. She said that, at the time, she couldn't understand why she had difficulty bonding with her second child. She credits her husband, singer Chris Martin, for recognizing her symptoms could be due to PPD.

Difficulties with sleep, low energy, and decreased interest in sex are some signs of PPD, but these can apply to even the happiest of moms.

Other clues that you may be experiencing more than just the reality of adjusting to a new baby in the household include:

• Feeling particularly overwhelmed, anxious, or like a failure.

• Being excessively irritable/angry.

• Being very tearful.

• Having thoughts of hurting yourself or your baby.

Talk to someone you trust — your partner, mother, or best friend — or seek counseling, if you feel you might have PPD.

Definitely mention it to your obstetrician who will be seeing you shortly after giving birth, and don't let the fact you are breast-feeding keep you from seeking help.

You and your doctor together can discuss the pros and cons of using medications to treat PPD.

Important: If you are having suicidal thoughts call 911 or the National Suicide Hotline: 800-273-TALK (8255) or www.suicidepreventionlifeline.org.

It is understandable to feel embarrassed or confused about any less-than-perfect feelings after giving birth, but remember that even Oscar winners (see Paltrow, above) can experience PPD and that there is help.

Linda Pourmassina, MD, is an Internal Medicine physician who practices at The Polyclinic in Seattle. She authors a blog at pulsus.wordpress.com and can also be found on Facebook and on Twitter (@LindaP_MD).