If you're waiting for test results, there are ways you can help prepare yourself.
Find out when you'll get your results. Jean Slocombe, senior cancer information nurse at Cancer Research UK, says: "It's always a good idea to ask when you can expect to get your test results and how you'll get them. If you don't hear anything for a few weeks, you may wonder if your results have got lost. Check up, as occasionally letters can go astray."
If you ever have any questions, ask. Most cancer charities have websites or helplines that can offer you advice and support.
Write down all the questions you might like to ask during your consultation. "It's very easy to forget what you wanted to ask because you may have to absorb a lot of information in a short time," says Jean.
That's what happened to Linda Hadley when she received her breast cancer diagnosis. "Everything just dashed through my mind and I couldn't think clearly," she says. "I'm glad I had my husband there to ask questions for me."
Another useful tip is to record your consultation on a dictaphone, but check with your doctor or consultant first. Either way, you should be offered a record of the consultation.
It's a good idea to have someone with you when you get your results. Breast Cancer Care's Carolyn Rogers says: "When you're frightened and anxious it can help to have someone there to be another pair of ears and support you.
"Having said that, some people just want to do it by themselves. You might find it useful to make notes or record the consultation so you can listen at home. It depends how you feel."
Neil Gooding, 43, was diagnosed with mouth cancer in 2005 and was living alone at the time. "My sister came along," he says. "I'd thought of questions I wanted to ask in advance, but it can be daunting. It was good to have someone on hand as a support."
If you don't want to ask someone you know to go with you, you may be able to ask someone from a local support group.
There's no right or wrong way to react to a cancer diagnosis. What matters most is that you have as much information as you need and feel comfortable with any decisions you make.
You might feel a range of emotions, including fear, anger or helplessness. Linda says she was in shock. "An absolute total numbness went through my body," she explains.
Nigel felt isolated. "I wanted to say to people around me on the street: 'Don't you realise...?' It felt strange that life just went on as normal."
Whether or not you confide in those close to you, it can often be helpful to get some support from someone who's not related to you. Many people and places are available to help.
Your nurse or specialist can give you information that's relevant to your situation and may be able to direct you to local support services, such as counselling and support groups, helplines and online forums.
Find out about the choices available to you, such as whether there's a specialist nurse you can talk things through with, for example. Read more about coping with a cancer diagnosis.
Write down questions as they occur to you and take these with you when you see your doctor. Here are some of the things you may want to ask:
healthtalk.org has articles and videos of people talking about their experiences of having cancer.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.