Yes, Alzheimer's disease usually worsens slowly. But its speed of progression varies, depending on a person's genetic makeup, environmental factors, age at diagnosis and other medical conditions.

Still, anyone diagnosed with Alzheimer's whose symptoms seem to be progressing quickly — or who experiences a sudden decline — should see his or her doctor. The doctor will look for complicating conditions or factors that can cause a rapid — but possibly reversible — progression of symptoms in someone with Alzheimer's disease. The doctor will also make sure that other causes of rapidly progressive dementia are excluded.

Such conditions and factors could include:

• Infections, such as pneumonia, a urinary tract infection or a sinus infection
• Reaction to some prescription medications, such as anticholinergics, narcotic pain relievers, sedatives, corticosteroids and some antidepressants
• Fatigue or lack of sleep
• Social or environmental changes, such as moving or the presence of new medical care staff or family members
• Vitamin deficiencies, including B-12, thiamin, niacin and folate
• Depression
• Thyroid problems, such as hypothyroidism
• Additional neurological conditions
• Autoimmune neurological disorders and paraneoplastic disorders, which are conditions that can cause rapidly progressive dementia

Seek a prompt and thorough medical evaluation to determine the exact cause of rapidly progressing symptoms. Additional treatment may be required, and it may be possible to reduce or reverse symptoms.