If a child seems confused about their gender, it's normal for parents to feel puzzled or worried. But it's important to support your child and not to jump to conclusions.
It's common and natural for very young children to show an interest in clothes or toys associated with the opposite gender.
Children under five may have little awareness that certain preferences are associated with one gender or other. If a three-year-old boy enjoys dressing in his sister's clothes, this probably means nothing in terms of how the child feels about his gender.
Even among older children, it's not uncommon for boys and girls to identify with the opposite gender, or to say they want to be the opposite gender.
Mermaids, a charity that provides support and information to children with gender identity issues and their families, says parents of younger children contact it more often about boys than about girls.
"This is probably not because gender-variant behaviour is more common in boys, but because a little girl who's a tomboy tends to be less of a concern than a little boy who plays with Barbies."
Parents tend to worry more about gender-variant behaviour in little boys because it presents more of a challenge to our assumptions about gender.
Will my child grow up to be transsexual or transgender?
Very few children who seem to be confused about their gender go on to live full-time as the opposite gender or be transgender (trans) as adults.
In many cases, the gender-variant behaviour or feeling disappears as the child gets older – often as they reach puberty.
Children who do continue to experience gender variance as they get older will develop in different ways. Some may feel they don't belong to any gender or have a gender. Others may want to dress in the clothes of the opposite gender from time to time, or on a regular basis.
Only a small number who have persistent and strong feelings of belonging to the opposite gender end up living full-time in the opposite gender.
When should I seek help for my child?
"If your child is very strongly identifying with the opposite gender, to the point where it's causing the child or the family distress, seek help," advises Ady Davis, a psychosexual therapist with the North-East Gender Dysphoria Service.
"Signs of distress in a young person or child can include self-harm, destructive behaviour and depression."
For young people who feel strong and persistent discomfort about their gender, puberty is often a very difficult time. The physical changes that occur at puberty can increase feelings of unhappiness about their body or their gender.
If your child is strongly identifying with the opposite gender, it's best to get help before puberty begins.
If the feelings of gender discomfort persist to the extent that your son or daughter wants to live full-time in the opposite gender, careful preparation needs to be made with the school and any clubs or groups your child attends.
Who can help?
For medical help, first visit your GP. The next step is usually referral to a local Child and Adolescent Mental Health Service (CAMHS) team, where psychological help will be offered to your child or teenager. This may involve working with the whole family, and sometimes with the school as well.
Depending on what services are available locally, some young people are referred to the gender identity service at the Tavistock and Portman NHS Foundation Trust in London. This is the only medical centre in the UK that specialises in helping children with gender variance.
Many parents find talking to other people who've had similar experiences is a great help in terms of finding out about gender variance and receiving support.
The charity Mermaids has a telephone helpline (020 8123 4819, Monday to Saturday) that parents can call for advice, information and support. The Mermaids website also has several real stories by young people and their parents.
For more information on gender identity in teenagers, read about coping with gender identity issues in your teens.
GPs and other health professionals may not have much experience with trans health issues or gender dysphoria. If you need to see a healthcare professional about your condition, it might be worth taking the latest guide on gender dysphoria services (PDF, 291kb) with you to your appointment.
This guide has been devised by doctors from gender identity clinics with input from interested groups, and outlines the best current NHS practice for gender reassignment services in England. You may also want to read this guide yourself to get a better understanding of what to expect from the NHS.
How can I support my child?
Sometimes children worry that if they tell you how they feel, you won't love them anymore. Mermaids' key advice to parents is: "Accept your child and let them know that no matter what their preferences are, no matter how they feel, you support them and love them."
Even if you feel concerned, try to be relaxed about cross-gender behaviour in your child. It's important children don't feel judged or rejected because of who they are.
If you feel anxious or uncomfortable, you're not alone. You may blame yourself because you think it's your "fault", but it's important to remember gender identity is nobody's fault.