Causes of Insomnia in People With Cancer

Causes of Cancer Related Insomnia

Insomnia in people with cancer is very common but has received little attention relative to the dangers it poses. Not only does insomnia significantly impact quality of life for people with cancer, but it appears to have a negative effect on the survival rate.

Since it is helpful to understand causes before discussing treatments, let's begin by outlining some of the causes and risk factors for insomnia in people with cancer. These include the biochemical changes associated with the growth of a tumor, cancer treatments, symptoms related to cancer and cancer treatments, as well as sleep routine and coexisting medical conditions.

Cancer Growth

The growth of a tumor by itself affects the biochemical and molecular processes taking place in the body. If you think about the sleep a growing teenager requires, the picture becomes more clear.

While there is little that can be done directly for this cause of insomnia (other than treating the cancer) it is a reminder that often many causes of insomnia and fatigue work together to cause symptoms. Controlling those causes over which people do have some control becomes increasingly important.

Physical Changes

When talking about physical changes accompanying a diagnosis of cancer, surgery is often the first thought. Surgical procedures for cancer can lead to insomnia in many ways. The repair process that takes after surgery increases biochemical processes which can, in turn, lead to insomnia and fatigue. In addition, sleeping during the day (such as with a general anesthetic) combined with the inevitable sleep disruptions at night to check on vital signs, can lead to a situation in which insomnia begins very early in cancer treatment.

Cancer Treatments

Both chemotherapy and radiation therapy can lead to cell death, which in turn leads to molecular changes predisposing to fatigue and sleep disruption. Many drugs used along with chemotherapy can alter sleep schedules as well.

Steroids, such as dexamethasone, often cause a state of hyperarousal for a few days, which in turn may be followed by a greater need for sleep. People with cancer may wish to work with their healthcare providers to schedule their chemotherapy infusions and does of steroids earlier in the day to help reduce this cause of insomnia. Small changes such as this can sometimes lead to large changes in how you feel.

Symptoms of Cancer and Treatments

There are many symptoms of cancer and cancer treatment which can play havoc with sleep. Some of these include:

• Pain
• Nausea and vomiting
• Peripheral neuropathy
• Cough
• Shortness of breath
• Hot flashes
• Itching
• Diarrhea 

Sometimes, taking the time to look at each of these symptoms individually, and making sure they are being optimally addressed, can make a significant difference in insomnia. For example, if hot flashes are causing significant sleep disruption there are a number of options (both medication and non-medication) that could reduce these symptoms, and hence, improve sleep.

Emotions

Common emotions that accompany a diagnosis of cancer can be brutal to the ability to fall asleep. As our minds review what is happening, the symptoms of anxiety and depression often seem amplified when the sun goes down.

Stress and the release of stress hormones also plays a role, and this stress can persist throughout life following a diagnosis of cancer. First, there is the stress of diagnosis, followed by the fear of recurrence or progression if a cancer is stable, or the fear of death if a cancer continues to progress or recurs. Managing stress (which requires stepping back and analyzing what you are most stressed about) can have a significant impact in controlling insomnia.

Physical Inactivity

Getting less exercise during the day can make sleeping at night more difficult, and there are many situations in which physical inactivity becomes the norm with cancer. Sedentary behavior can be forced by hospitalizations, chemotherapy sessions, radiation sessions, travel for oncology visits, and due to the pain and side effects of cancer itself.

Co-Existing Medical Conditions

Medical conditions in addition to cancer are an important cause of insomnia. A few conditions which are strongly correlated with insomnia include:

• Sleep apnea is a common condition marked by short periods of apnea (literally, no breath) during the night. You may associate sleep apnea with snoring, but there are many surprising signs of sleep apnea to keep in mind as well.
• Thyroid problems are common in general and may occur in relation to cancer, chemotherapy, immunotherapy, and more. If other causes don't seem to be adding up to cause your insomnia, ask your healthcare provider about this possibility. It's thought that hypothyroidism is greatly underdiagnosed in the United States.

Noting that other medical conditions may be leading to your insomnia is very important, as it can be easy to dismiss any symptom as being due to the cancer. Again, elucidating the causes of insomnia sometimes requires stepping back enough to look for non-obvious factors.

Environment

If you have ever tried getting a good night's rest in the hospital, you know how important it is to have a good sleep environment. Noises, bright lights, and a television can all disrupt sleep initiation. There are certainly times that the hospital is the best place to be, but even in the hospital, there are measures you can take to improve your environment. Sometimes little things, such as pulling a curtain, or moving to a room where there is less commotion, could make a big difference.

It's not just the physical environment that can be noisy. Thinking about your fears, about discussions with friends or family members who have upset you, or trying to write a to-do list in your mind, can lead to "noisy thoughts" that keep you up as well.

Poor Sleep Habits

People who ditch the bedtime routine have more difficulty falling asleep. It takes a while for the body to calm down after watching the news or discussing a stressful topic. Sometimes all that is needed to eliminate this cause of insomnia is a regular sleep schedule preceded by habits which let your body know that it's time to rest.

Excess time spent in bed, or napping for an extended period of time in the late afternoon, can make it difficult to fall asleep at night. Having unrealistic sleep expectations may also be a factor in insomnia. If your body is healing from cancer treatments you may require more sleep—but not necessarily an entire day spent in bed.