Symptoms – Unexplained Weight Loss

Blood cancers can cause some general symptoms that may also be caused by other conditions, such as weight loss. When blood cancers cause weight loss as an early symptom of the disease, it is typically unexpected weight loss, or weight loss that occurs without trying to lose weight. An estimated 40% of people with cancer (all types of cancer) experience unexplained weight loss when they are first diagnosed.1

What causes weight loss in blood cancer?

Blood cancer may cause weight loss because the cancerous cells are using up much of the body’s energy supplies. Cancerous cells can grow quickly, impacting the body’s normal functions. Some cancer cells may also produce substances that change the way the body creates energy from food that is eaten (metabolism).1,2

Weight loss that occurs with blood cancers and other cancers may also be caused by a lack of appetite. When appetite is lessened, people eat less than usual, and weight loss can occur.1

Weight loss is also commonly seen during treatment of blood cancers, as some treatments can cause side effects of nausea, vomiting, mouth sores, or a change in how foods taste. Some people undergoing treatment for blood cancer may also experience depression, and depression can cause a lack of interest in food, which can lead to weight loss.1

Other symptoms of blood cancer

Weight loss is frequently accompanied by fatigue or lack of energy, and these symptoms may make it difficult to perform daily activities. In addition to weight loss, other general symptoms that may be caused by blood cancer include:

While these general symptoms may be caused by blood cancer, they can also be caused by many other conditions. It’s important to have these or other symptoms evaluated by a healthcare professional to get a proper diagnosis.

The cancerous cells in blood cancer can crowd out healthy blood cells, including red blood cells, white blood cells, and platelets. When the healthy blood cells are negatively impacted, blood cancers can cause additional symptoms, such as:

  • Shortness of breath
  • Dizziness or feeling lightheaded
  • Headache
  • Repeated infections, or infections that won’t go away
  • Fevers, especially without an obvious cause
  • Frequent bruises, especially without a clear reason
  • Easily bleeding, such as from cuts, from the gums, or frequent nose bleeds
  • Small, pinhead-sized red spots on the skin (called “petechiae”) 2,3

It’s important to remember that not everyone with blood cancer experiences all these symptoms. There are many different types of blood cancer, each with its own unique list of symptoms, and each individual has a unique experience and combination of symptoms.

Diagnosing blood cancer

To diagnose blood cancer, doctors may use several tests, including a physical exam, medical history, blood tests (like a complete blood count, blood chemistry, blood smear, and blood clotting tests), bone marrow aspiration and biopsy, lymph node biopsy, lumbar puncture, and imaging tests (like a chest x-ray, computed tomography (CT) scan, magnetic resonance imaging (MRI), or ultrasound). Some of these tests are also used to rule out other conditions.2

Written by: Emily Downward | Last reviewed: February 2018
View References
  1. Weight loss, Cancer.net. Available at https://www.cancer.net/navigating-cancer-care/side-effects/weight-loss. Accessed 10/30/17.
  2. Signs and symptoms of cancer, American Cancer Society. Available at https://www.cancer.org/. Accessed 10/30/17.
  3. Leukemia & Lymphoma Society. Available at http://www.lls.org/. Accessed 10/30/17.