But, for the 15 million in Britain affected by some kind of long-term symptoms, it can also signal a complete change in how they live their lives.
The day Bob Hamilton (64), from Polmont, learned he had cancer is still fresh in his mind.
''I was diagnosed on July 12, which will be two years ago this summer,'' he said. ''My prognosis was bleak and I was absolutely devastated at the time.''
It was nearly 10 years ago when Anne Brown (50), from Carron, was diagnosed with MS.
She said: ''After four and a half years of worry and anxiety, my first reaction was actually relief that I knew what was wrong.
''But the variability of MS means people react differently – my mum thought I was going to be in a wheelchair.
''It also forced me to leave my job. I wanted to continue working part-time, but they refused and told me I would have to be demoted to deputy manager and put on a lower wage.
''It was against the law, so I took legal action and we settled out of court.''
But Bob, Anne and many others have managed to overcome these problems, thanks in a large part to a local self-management course, run by volunteers from the MS Society and Arthritis Care.
The classes are unique in that the course leaders themselves have a long-term condition and therefore have an acute understanding of the problems that people face.
Open to anyone with a long-term condition, it's designed to help people manage their symptoms more effectively and learn to take control of their own lives again.
March sees the start of this year's classes, which will take place in Polmont's Greenpark Community Centre.
It will be the third time that Bob has attended.
He said: ''I wouldn't be going back again if it hadn't been a really good help.
''Before I went the first time, I felt really ill and miserable, but the course was absolutely brilliant. I took so much out of it."
Anne is secretary of the Falkirk branch of the MS Society and is the volunteer course leader.
She said: ''The programme was first developed in America and then came to England. Their experience was that people who were already affected with the condition were the best ones to comment on the condition to others.
''There were no schemes going on up here so we decided to join up with Arthritis Care and start our own group.''
Some of the tools which people can expect to learn on the course include improving communication with family, friends and medical professionals; techniques to help deal with problems brought on by their illness; and planning for the future.
Before qualifying to take classes, Anne had to attend a crash course as a participant.
''I really didn't know what to expect, and since it took place over two days it was very intense, but I thought it was absolutely brilliant. I came out of it feeling very emotional,'' she explained.
Bob added: ''Everything they have told me has helped.
''They give you great advice, teach exercises to relieve stress, and, if you are not sure why you are on your medication, they tell you how to go and check it out with your doctor.''
The classes also provide a private space for people to discuss their experiences and to support one another.
''Everyone is in the same boat so you can say things that you wouldn't say outside or in front of your family,'' said Anne.
''People may feel that family and others are making decisions for them, so it gives them a chance to become more independent.''
Bob added: ''It's great you can discuss things in there about your condition and know what is said will never leave the room. I wouldn't want my family to hear it as it would just depress them.
Seeing the participants take control of their own lives again, is an inspiration reveals Anne.
''You get so much satisfaction from seeing them taking their own actions again and the feedback we get is fantastic – people have even said that it has changed their lives,'' she said.
''Overall the benefits for me have been fantastic. I feel like I can live my life again,'' added Bob.
m.henderson@falkirkherald.co.uk
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