Insomnia diagnosis

There is no one test used to diagnose insomnia. You may be referred by your healthcare provider to a sleep specialist in order to receive the most in-depth diagnosis and treatment for your condition.

Generally, diagnosing insomnia¹⁷ involves one or more of the following:

• Physical examination: Your healthcare provider may perform a physical exam to determine the cause of your insomnia. A blood test may be done to look for any signs of underlying medical conditions—such as thyroid problems and other sleep conditions—that may be contributing to your signs and symptoms.
• Review of sleep habits: Your provider may ask questions and administer a questionnaire to better understand your sleeping habits. Keeping a sleep journal (in which you track the amount and quality of sleep you get) from the moment you start to notice your symptoms can be helpful in this process. If you haven’t yet started a sleep journal, you may be asked to track your sleep habits for a few weeks.
• Overnight study: If the cause of your insomnia has not been determined or you’re showing signs of another related disorder (such as sleep apnea or RLS), you may be asked to undergo an overnight study. This will allow a specialist to more closely analyze your sleeping behaviors. In an overnight study, several body systems and activities are monitored, including breathing, heartbeat, eye movements, brain waves, and body movements.

Fatal familial insomnia

Fatal familial insomnia (FFI)¹⁸ is a rare genetic disease that causes an inability to sleep. It’s often caused by a mutation of the prion-related protein (PRPN) gene but may also occur randomly (without the abnormal PRPN gene) as sporadic fatal insomnia (SFI).

The PRPN gene is responsible for regulating the production of the prion protein. When it’s altered, misfolded prion protein (which is toxic to the human body) is generated. These prions build up different areas of the brain, causing prion disease. FFI is just one of these diseases—others include Gerstmann-Straussler-Scheinker syndrome and Creutzfeldt-Jakob disease.

People with FFI experience insomnia that may start mildly but progressively worsens, causing physical and mental deterioration. The autonomic nervous system (which controls involuntary bodily functions) may also be affected, leading to complications in regulating breathing, body temperature, heart rate, or other automatic body processes. Other symptoms (which may not always be present in all individuals) include progressive dementia, double vision (diplopia), nystagmus (repetitive, uncontrolled eye movement), dysphagia (difficulty swallowing), and dysarthria (slurred speech).

There is no cure for FFI, but research is ongoing to find treatment and better ways of managing the condition. Currently, treatment for FFI usually requires the coordination of several specialists working to manage specific symptoms of the disease as they appear.