Friendships can be as tumultuous as the most passionate love affair. Susan Quilliam outlines common friendship problems and explains how to deal with them

Who's the first person you want to celebrate with when you're happy and the only one you want to be with when you're down? Often it's your best friend rather than your lover. The only trouble is that as much as you love your friends, you can also find them annoying, frustrating and even hurtful.

So what should you do with friends that drive you crazy - and what can you do with a friendship when it's gone sour?

Flaky friend
What's happening? She never quite gets anything together, particularly where you're concerned. She doesn't return your calls, she sometimes stands you up, she disappears for months at a time. You love her dearly but you'd like her to be a bit more reliable.

What to do? If your friend is like this with everyone, then the way to keep the friendship going is not to rely on her. Accept that she's not constituted to follow through - and just enjoy her company whenever.

But if you're singled out for the unreliability, it suggests she doesn't value your friendship. May be it's time to start thinking whether she's worth all the effort you put into the relationship.

Needy friend
What's happening? She rings you daily with an update on her chaotic life. It's just temporary - perhaps a romantic tragedy has made her particularly vulnerable. But temporary can easily turn to permanent if she gets into the habit - and you end up feeling that it's one-way traffic in the support department.

What to do? Work within your limits. It's no good for you if you are giving more than you feel able, and she will just become more dependent and that's no good for her.

So, if she rings at an awkward time, let her know instead of guiltily letting her ramble on. If she talks about her own problems throughout supper, turn the conversation back to you sometimes. Express your own needs - and invite her to support you over your problems.

Competitive friend
What's happening? She loves to compete - and often, she wins. If you lose weight, she loses more. If you get a good job, she immediately changes career. If you get - or dump - a new man, she's right behind you in the romance stakes. You feel you can't do anything without her outdoing you.

What to do? Realise that she does this only because she feels insecure - and that if she's simply following in your footsteps, she'll never feel satisfied. Then simply opt out of the competition. You should aim for what you want in life, and make sure you are happy. If she carries on competing, that's her problem.

Perfect friend
What's happening? Your friend is great - too great. She's pretty, bright, good at her job - and/or has the men flocking round her like bees to a honey pot. In the face of your friend's success you feel a failure - and your envy makes every meeting with her a trial.

What to do? Remember that your feelings are your problem - and are a result of your insecurity. Of course, if your friend is simply hanging round with you to make herself look good, then you need to pick better friends. But if she's a genuine friend to you, then be a genuine friend to her - and try to feel happy for her success rather than undermining it. Plus, work on your self-confidence - the better you feel about you, the better you'll feel about her.

Flirty friend
What's happening? She loves flirting - the problem is, her targets include your boyfriend. She may not seriously want your man but she wants to assure herself of her sexual power and that means flirting whenever possible.

What to do? Don't have a tantrum, but do warn her off. Tell her to back off.

If she persists, stop seeing her when you're with your man. If he persists, think carefully about whether you're in the right relationship.

Dominating friend
What's happening? Quite simply, she wants things her way. And probably when you first met, that was fine by you. The fact she was sure of herself made her more fun to be around. But perhaps, as time went by she became more dominant - or you became more confident. Now she's so wilful it makes it difficult for you to have a balanced friendship.

What to do? Try standing up to her. If she doesn't realise that her bossiness is irritating, then it's unfair to expect her to change.

So next time she makes a unilateral decision and expects you to follow, express your point of view. If she argues, state your case calmly. If she continues to argue, do what you want to do and invite her along.

It may help to read When Friendship Hurts, Jan Yager, published by Simon and Schuster.