Most of us know about the emotional symptoms of depression. But you may not know that depression can cause physical symptoms, too.In fact, many people with depression feel pain or other physical symptoms. These include:

   Headaches. These are fairly common in people with depression. If you already had migraine headaches, they may become worse if you're depressed.
   Back pain. If you already suffer with back pain, it may get worse if you become depressed.
   Muscle aches and joint pain. Depression can make any kind of chronic pain worse.
   Chest pain. Obviously, it's very important to get chest pain checked out by an expert right away. It can be a sign of serious heart problems. But chest pain is also associated with depression.
   Digestive problems. You might feel queasy or nauseous. You might have diarrhea or become chronically constipated.
   Exhaustion and fatigue. No matter how much you sleep, you may still feel tired or worn out. Getting out of the bed in the morning may seem very hard, even impossible.
   Sleeping problems. Many people with depression can't sleep well anymore. They wake up too early or can't fall asleep when they go to bed. Others sleep much more than normal.
   Change in appetite or weight. Some people with depression lose their appetite and lose weight. Others find they crave certain foods -- like carbohydrates -- and weigh more.
   Dizziness or lightheadedness.

Many depressed people never get help, because they don't know that their physical symptoms might be caused by depression. A lot of doctors miss the symptoms, too. These physical symptoms aren't "all in your head." Depression can cause real changes in your body. For instance, it can slow down your digestion, which can result in stomach problems.

Depression seems to be related to an imbalance of certain chemicals in your brain. Some of these same chemicals play an important role in how you feel pain. So many experts think that depression can make you feel pain differently than other people.

Health experts' understanding of depression has come a long way in the last few decades. In many cases, depression doesn't have only one cause. It often results from a mix of biology, psychology, and stressful or traumatic events.

   Biology. Researchers still have a lot to learn about exactly why people become depressed. But some experts say depression often results from an imbalance of certain chemicals in the brain. These chemicals are called neuro-transmitters. Anti-depressants work by affecting the levels of these chemicals -- bringing them back into balance.

There's also a genetic connection. If depression runs in your family, you have a higher chance of becoming depressed.

Having other health conditions or diseases can increase your risk of depression. For instance, if you have a heart attack, you have a 65% risk of becoming depressed afterwards. Conditions such as cancer, heart disease, thyroid problems, and many others increase your risk of becoming depressed.

Your gender makes a difference, too. Women are about twice as likely as men to become depressed. No one's sure why. But the hormonal changes that women go through at different times of their lives may be a factor.

    Psychology. Studies show that people who have a pessimistic personality are more likely to become depressed. This doesn't mean that getting a "better attitude" will resolve your depression.
    Stressful events. Many people become depressed during difficult times. Losing a family member or close friend, being diagnosed with a serious illness, going through a divorce, or any other traumatic event may trigger depression.
    Medications and substances. Many prescription drugs can cause the symptoms of depression. Alcohol or substance abuse is common in depressed people. It often makes their condition worse.

Some people have a clear sense of why they become depressed. Others don't. The most important thing to remember is that depression is not your fault. It's not a flaw in your character. It's a disease that can affect anyone.

The good news about depression is that you have a number of excellent treatments to choose from. More than 80% of people who get treatment for depression say that it helps them feel better.

Here's a rundown of some of the most common approaches. Many people use a mix. For instance, you might try medicine and therapy at the same time. Some studies show that using both together is better than using either one alone.

In some cases, treating your depression -- with therapy or medicine or both -- will resolve your physical symptoms. But make sure to tell your health care provider about any physical symptoms. Don't assume they'll go away on their own. They may need additional treatment. For instance, your doctor may suggest an anti-anxiety medicine if you have insomnia. Those drugs help you relax and may allow you to sleep better.

Since pain and depression go together, sometimes easing your pain may help with your depression. Some anti-depressants, such as Cymbalta and Effexor, may help with chronic pain, too.

Other treatments can also help with painful symptoms. Certain types of focused therapy -- like cognitive behavioral -- can teach you ways to cope better with the pain.

Talking with a trained therapist is one of the best treatments for depression. Many studies show that it helps. Some people choose to be in therapy for several months to work on a few key issues. Other people prefer to stay in therapy for years, gradually working through larger problems. The choice is up to you. Here are some common types of therapy.

    Cognitive behavioral therapy helps you see how behaviors -- and the way you think about things -- play a role in your depression. Your therapist will help you change some of these unhealthy patterns. This is a very hands-on approach.
    Interpersonal therapy focuses on your relationships with other people and how they affect you. Your therapist will also help you identify and change unhealthy behaviors.
    Psychodynamic therapy is a more traditional form of therapy. It focuses on the deeper roots of your problems. Your therapist might encourage you to talk about hard things in your past, especially your childhood. This type of therapy is often done during a longer period.

Medicines are the other key treatment for depression. There are now dozens of antidepressants that your health care provider can choose from. They include:
   SSRIs (selective serotonin reuptake inhibitors.) These common medicines include some well-known names, like Lexapro, Paxil, Prozac, and Zoloft. Side effects are generally mild. They include stomach upset, sexual problems, insomnia, dizziness, weight change, and headaches.
   Newer types. Researchers have developed many new types of antidepressants in recent years. These include drugs like Wellbutrin, Cymbalta, and Effexor. Cymbalta and Effexor may also ease chronic pain in people with depression. Side effects are usually mild. They include stomach upset, sleep problems, sexual problems, dizziness, and weakness.
   Older antidepressants. Tricyclic antidepressants and Monoamine Oxidase Inhibitors (MAOIs) were some of the first medicines used to treat depression. While they work well, they can cause serious side effects and interact with some drugs and foods. Because newer medicines work just as well, these drugs aren't used as often anymore. But if you can't take newer medicines for some reason, your health care provider may suggest these.

This is a safe and effective treatment for people with serious depression. It's typically used on people who haven't been helped by medicines or therapy.

In ECT, your doctor will use electric charges to create a controlled seizure. These seizures seem to change the chemical balance of the brain. It may sound scary. But during the procedure, you'll be unconscious, so you won't feel anything.

ECT tends to work very quickly. It also works well -- about 80%-90% of people who receive it show improvement. The most common side effect is temporary memory loss.

You might have up to 12 sessions over a few weeks. Some people get "maintenance" therapy with ECT to prevent depression from returning.

Vagus Nerve Stimulation (VNS) is a new option for people with severe, treatment-resistant depression. Approved by the FDA in 2005, it's used only on people who haven't been helped by at least four antidepressants.

VNS involves implanting a small electrical generator in your chest, like a pacemaker. The device is attached with wires to the vagus nerve, which runs from the neck into the brain. Once implanted, the device sends electrical pulses to the vagus nerve every few seconds. The pulses are then delivered via the vagus nerve to the area of the brain thought to regulate mood. The electrical charges may change the balance of chemicals in your brain and relieve depression.

The device must be implanted by a surgeon, but patients can usually go home the same day.

Some people use herbs, supplements, and other alternative therapies for depression. However, none of these approaches has been proven to work. Herbs and supplements -- like St. John's Wort -- can have side effects and cause interactions with other medicines. Never start taking an herb or supplement without talking to your doctor first.

Other unproven alternative treatments -- like acupuncture, hypnosis, and meditation -- may help some people with their symptoms. Since they have few risks, you might want to try them, provided that your health care provider says it's OK.