"Can I work if I have Parkinson's disease?"
It is not only possible to work with early onset Parkinson's disease, it is probable. Most people who were working prior to diagnosis continue to work for some period of time afterwards.
"How long will I be able to work?" This is usually the more difficult question to answer. The length of time each person continues working will depend on many different factors. Some will be related to the disease itself such as symptoms, medication side effects, or progression of the disease; others are likely to be environmental factors including the overall economy and your particular employer.
When it comes to PD in the workplace, it can be helpful to think of symptoms as internal and external as motor symptoms and non-motor symptoms. External symptoms are those your employer, co-workers or clients may notice such as tremor, slowness, rigidity, facial mask, etc.and those that involve more internal processes such as fatigue, sleepiness, apathy or difficulty concentrating/multi-tasking. While not every person will experience all of these symptoms, developing a plan for how you may handle or explain symptoms that do occur have can be very helpful and reduce stress.
Some people work hard to keep their boss/colleagues from discovering that they have Parkinson's disease, oftentimes out of fear of job loss. Others have found their boss/colleagues to be a tremendous source of support. In fact, some employers have gone so far above and beyond what their PD employees expected, those employees have nominated them to receive our "Certificate of Appreciation." Having PD does not necessarily mean that you have to quit your job or be forced into retirement. Many employers are willing to stand by their employees and cooperate to find a plan and schedule that works for both parties.
Even if you do not intend to stop working any time soon, it is advisable to make contingency plans. Sometimes a career change or move to a less stressful job with more flexible hours or one that allows you to work from home will help you remain in the workforce. In fact, it is usually more difficult for younger people to qualify for Social Security Disability Income (SSDI) , as the Social Security Administration (SSA) prefers to see "younger individuals" [PDF] (those under the age of 50) retrain or transfer their skills to another type of work.
Regarding employment, keep in mind that careful planning and deliberate decision-making are likely to lead to easier transitions and a better future.