Feeling let down by someone? The ultimate solution may lie in your own hands, writes Tony Humphreys.

Disappointment is an emotional and psychological experience and can have the same telling effects of such powerful emotions as love, hate, fear, sadness, grief, anger and jealousy. The expression "I'm disappointed in you" can strike a devastating blow and is a clear message that you have not lived up to expectations.

You can experience disappointment in three ways: the first is where you feel disappointed in another, the second, in yourself and the third, when another expresses disappointment in you.

When you feel disappointment in a relationship, generally speaking, important needs, expressed or unexpressed, have not been met and your feelings of disappointment give testament to "being let down". This can occur in all relationships between husband and wife, lover and lover, friend and friend, employer and employee, parent and child and teacher and child.

When parents say to a son or daughter "You're a disappointment to us", they are expressing their anger at their child not turning out the way they wanted. The disappointment may be around their son or daughter's choice of friend, university course or career; it may also have to do with some behaviour that in their eyes has brought shame on the family - teenage pregnancy, taking drugs, being drunk, stealing, lying and so on. However, true love and effective parenting is born from understanding and the judgement and condemnation in such an expression of disappointment shows no glimmer of such maturity.

You might say to me: "But I am feeling disappointed and what are you going to do about that?" All feelings, including disappointment, are messages to the person experiencing them and you must own, interpret and take the responsible action prompted by the feelings.

When disappointment has arisen from unmet needs, then detecting and taking responsibility for those needs is required. It is not anyone else's responsibility to meet your needs - that is your task. You have every right to make requests around unmet needs, but it may often be the case that the other person is not in a place to respond to those needs.

Some feelings of disappointment arise when the other person is not living their life according to your wishes, but then each person is here to live their own life and respect and cherishing that freedom makes for far less disappointment in others. Certainly, when your reasonable needs continue to be unmet, then action on your part will be required.

The expression "I'm disappointed in you" can vary in depth and intensity. Probably the expression "bitter disappointment" conveys most powerfully the intense hurt and anger experienced when entirely reasonable expectations have not been met. However, no matter how reasonable expectations are, meeting them ultimately lies at your door.

When you feel disappointed in yourself, that in some way you have let yourself down, the feeling signals a need for you to reflect on some aspect of your behaviour.

When another expresses disappointment in you, it is important to listen and to understand that it is not a criticism of you, but an attempt by the person to express some unmet need. If you react, conflict will ensue; if you proact, then resolution is possible.

A reaction could take the form "I'm sick of your complaining"; a proaction would gently enquire "tell me more about what you are feeling disappointed about?" It is essential that the receiver, rather than becoming the rescuer, enables the other person to get in touch with their unmet needs and the action required to meet those needs.

Dr Tony Humphreys is a consultant clinical psychologist and author of Myself, My Partner