Bipolar disorder, also known as manic depression, is a serious mental illness that can lead to risky behavior, damaged relationships and careers, and even suicidal tendencies if it's not treated.

Doctors don't completely understand the causes of bipolar disorder. But they've gained a greater understanding in recent years of the bipolar spectrum, which includes the  highs of mania to the lows of  depression, along with various mood states in between.

A bipolar disorder diagnosis is made only by taking careful note of symptoms, including their severity, length, and frequency.

More than 10 million Americans have bipolar disorder. It affects men and women equally, as well as all races, ethnic groups, and socioeconomic classes.

Although bipolar disorder more commonly develops in older teenagers and young adults, it can appear in children as young as 6.

Bipolar disorder occurs with similar frequency in men and women. But there are some differences in the way they experience the condition.

While bipolar disorder cannot be prevented, early recognition of warning signs and seeing your doctor regularly can allow you to monitor your mood and medications and keep the illness from escalating.