Your mood is influenced by many things — the good, as well as the bad.

Spending time with a loved one or friend can improve it. Sitting in an hour of unexpected traffic can ruin it.

But your mood is more complicated than the situations and environments you encounter. There's brain chemistry to consider, too.

In between sensing a situation and responding to it, chemicals called neurotransmitters and hormones help your brain understand, evaluate and communicate what you're experiencing. These various neurotransmitters and hormones have specific jobs — each being activated in a certain way, signaling certain emotions and stimulating certain areas of your brain.

When it comes to happiness, in particular, the primary signaling chemicals include:

• Serotonin
• Dopamine
• Endorphins
• Oxytocin
  
  

Here's what you need to know about these happy hormones, including tips for activating the feel-good brain chemistry they provide to help improve your mood: