Headaches are a common experience, but for individuals with a cancer diagnosis, their presence can raise concerns. While most headaches are not related to cancer, cancer can cause headaches through various mechanisms. This article explores how cancer can lead to headaches, other contributing factors, and when a headache warrants medical attention.
How Cancer Directly Causes Headaches
Cancer can directly cause headaches when it develops in or spreads to the brain or spinal cord. The brain itself does not contain pain receptors, but surrounding structures like the dura and blood vessels are sensitive to pressure and inflammation. A growing tumor can increase pressure inside the skull, leading to a headache. This increased intracranial pressure can result from the tumor’s mass, associated swelling (edema), or by blocking cerebrospinal fluid flow, which cushions the brain and spinal cord.
Headaches caused by brain tumors are often described as dull or pressure-like. These headaches might be constant and tend to be worse at night or in the early morning. They can also intensify with activities like coughing, sneezing, or straining, which further increase intracranial pressure. While primary brain tumors originate in the brain, metastatic tumors, which spread from other parts of the body, are a more common cause.
Other Reasons for Headaches in Cancer Patients
Headaches in cancer patients extend beyond direct tumor involvement and can arise from various other factors, including cancer treatments and systemic effects of the disease. Chemotherapy, radiation therapy, immunotherapy, and hormonal therapies can induce headaches as side effects. For example, some chemotherapy drugs can directly cause headaches, and radiation to the head or neck area can lead to inflammation and swelling.
Systemic effects of cancer can also contribute to headaches. Anemia, a common condition in cancer patients characterized by a low red blood cell count, can cause headaches due to reduced oxygen delivery to the brain. Dehydration, often a consequence of vomiting, diarrhea, or poor appetite, is another common trigger. Infections, such as sinusitis or meningitis, can also occur in cancer patients, particularly those with weakened immune systems, and cause headaches. Additionally, rare paraneoplastic syndromes, where the immune system mistakenly attacks healthy cells in response to a tumor, can sometimes involve the nervous system and lead to headaches.
When to Be Concerned About a Headache
Certain headache characteristics warrant medical attention, especially for individuals with a cancer diagnosis. A headache that is new, unusually severe, or progressively worsening should be evaluated by a healthcare provider. Headaches that awaken an individual from sleep or are worse in the morning are also concerning signs.
Other important indicators, often called “red flags,” include headaches accompanied by new neurological symptoms. These can manifest as changes in vision, such as blurred or double vision, or loss of sight. Weakness or numbness on one side of the body, speech difficulties, confusion, personality changes, or new seizures also signal a need for prompt medical assessment. Headaches that do not respond to over-the-counter pain medications or those exacerbated by coughing, sneezing, or straining should also be discussed with a doctor.
Medical Evaluation for Headaches
When a headache raises concern, particularly in the context of cancer, a thorough medical evaluation is important. This evaluation typically begins with a detailed medical history, where the healthcare provider will ask about the headache’s characteristics, including its onset, intensity, and any accompanying symptoms. A physical and neurological examination will also be performed to assess reflexes, coordination, vision, and mental status.
Imaging studies are often a next step to investigate the cause of concerning headaches. Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scans of the brain can help identify structural issues such as tumors, swelling, or other abnormalities. Communicating all symptoms and providing a complete medical history, especially regarding any cancer diagnosis or treatment, is important for guiding the diagnostic process.