Are you in the middle of a friendship that isn't turning out the way you'd hoped it would? Is your previously supportive, reliable, loving bff disappointing you? Draining you? Hurting you? Is she making unreasonable demands? Breaking her promises? Betraying a confidence? If so, take comfort in the fact that you're not alone.

In truth, best friends often don't last forever. Our teenage years are full of life-altering challenges—physical, emotional, academic and social. All these changes feed our insecurities, spark envy and jealousy, and can cause huge shifts and upsets with the people we are closest to. The term toxic friendship refers to a variety of relationships that are consistently negative. Patterns develop that can make you feel you're walking around with an emotional ball and chain around your heart. If you find you have a toxic friend, one that feels out-of-synch, you must decide if it's more trouble than it's worth...and if it's time to call it quits.

Girls have a hard time extricating themselves from a toxic friend. We aren't always sure we deserve to receive what we give. We like feeling needed. And we get stuck, feeling either angry or sorry for our unsatisfying friend. It seems easier to overlook, forgive, and forget than to change the landscape of your life so drastically. Before deciding whether your friendship is beyond repair, think about these questions. Sometimes the situation is crystal clear (stealing your boyfriend, for example) but sometimes the red flags of a toxic friend are more subtle.

Toxic Friend Red Flag 1: Is she self-centered, sneaky, deceitful, or disloyal?

Toxic Friend Red Flag 2: Does she take the time to listen to you, support your interests, and get excited when things go your way?

Toxic Friend Red Flag 3: Does she show off at your expense?

Toxic Friend Red Flag 4: Is she constantly finding fault with you, criticizing what you do, say or wear?

Toxic Friend Red Flag 5: Do you come away from her feeling depressed? Tense? Trapped?

Toxic Friend Red Flag 6: Are your secrets safe with her? Or do you worry that she'll gossip and betray your confidence? Is she trustworthy?

Toxic Friend Red Flag 7: Does she care about what you say? Does she get it? Or does she just use you as a sounding board?

Toxic Friend Red Flag 8: Is she obviously competitive, always trying to one-up you?

Another way to determine whether this friendship is worthwhile is to think about how you feel when you're planning to see her. Is it more of an obligation than a pleasure? When her name pops up on your phone or on the computer, do you look forward to answering? If the answer is no, it might be time to address the problem and initiate a break. All relationships are about the right fit. It's a difficult but natural part of life for two friends to drift apart and pursue different paths. If you're not connecting or clicking as you once did, it doesn't mean one of you is any better than the other. It just might mean you're not meant to be friends right now.