Fatigue, an occasional fever or a bruise after an accidental bump are symptoms most of us tend to dismiss. And in most cases, there is no reason for concern. Tiredness can follow a stressful week, fever commonly accompanies an infection, and bruises can appear without us remembering exactly how they happened.

When any of these symptoms are persistent, recurrent, unexplained or occur in combination with one another there is concern. Since they can be the first clues to a problem affecting the blood or bone marrow in some situations. Blood cancers, including leukaemia, lymphoma and multiple myeloma, can initially present with symptoms that appear quite ordinary. This is why knowing when to investigate is important.

When Fatigue Is More Than Just Tiredness

Everyone feels tired occasionally. What deserves attention is fatigue that persists despite adequate sleep and begins to interfere with normal activities.

In some blood cancers, particularly leukaemias, abnormal cells in the bone marrow interfere with the production of normal blood cells. A reduction in red blood cells can cause anaemia, leading to persistent tiredness, weakness, breathlessness on exertion, dizziness or reduced exercise tolerance.

Of course, anaemia itself is very common and has many possible causes, including iron deficiency, vitamin deficiencies, chronic illnesses and blood loss. A blood test helps distinguish between these possibilities.

Fever That Keeps Coming Back

Fever is usually the body's response to infection. But if a person has recurrent or unexplained fever, particularly when there is no obvious infection, it should not simply be treated repeatedly with medication without looking for the underlying cause.

Some blood cancers can cause fever because of the body's immune response to the disease. In lymphoma, for example, unexplained fever can occasionally occur along with other symptoms such as night sweats and weight loss.

A persistent fever does not mean someone has cancer. Infections, autoimmune conditions and several other illnesses are much more common explanations. The important point is that an unexplained, persistent fever deserves appropriate evaluation.

Bruising Or Bleeding Without An Obvious Reason

A few bruises after physical activity are usually harmless. However, frequent bruising, unusually large bruises, nosebleeds, bleeding from the gums or prolonged bleeding from minor cuts may indicate a problem with platelets or blood clotting.

Platelets are produced in the bone marrow and play a crucial role in preventing bleeding. When platelet numbers fall, bruising and bleeding can occur more easily.

A complete blood count (CBC) is one of the simplest and most useful initial investigations in this situation. It measures haemoglobin, white blood cells and platelets and can provide important clues about what is happening in the blood and bone marrow. This test combined with examination of the blood by a trained pathologist known as peripheral smear can add great value in diagnosis of serious blood disorders.

Other Symptoms That Should Not Be Ignored

Blood cancers do not have one characteristic symptom. Depending on the type and stage of disease, a person may experience:

  • Unexplained weight loss
  • Persistent or drenching night sweats
  • Recurrent infections
  • Swollen lymph nodes, particularly if they persist or continue to enlarge
  • Pale skin or increasing breathlessness
  • Bone or persistent body pain
  • Abdominal fullness or discomfort due to an enlarged spleen or liver
  • Persistent weakness or reduced stamina

These symptoms are not specific to blood cancer. Most people experiencing one of them will not have cancer. It is the persistence, progression or combination of symptoms that should prompt a closer look.

What Does A Blood Test Actually Tell Us?

A CBC is often the first step. It can identify abnormalities in haemoglobin, white-cell counts and platelets. Depending on the findings and the clinical picture, a doctor may recommend additional tests such as a peripheral blood smear, iron and vitamin studies, kidney and liver function tests, inflammatory markers or infection-related investigations.

If the results raise suspicion of a blood disorder, further evaluation may include specialised blood tests, imaging, bone marrow examination or other tests depending on the suspected diagnosis.

Importantly, a blood test does not by itself diagnose every blood cancer. Some lymphomas, for instance, may have a completely normal CBC. Diagnosis may require examination of a lymph node or another involved tissue, along with imaging and specialised laboratory tests.

When Should You See A Doctor?

There is no single duration that applies to everyone. A practical approach is to seek medical advice when a symptom is persistent, recurrent, unexplained, getting progressively worse or associated with other concerning symptoms.

For example, unexplained fatigue accompanied by weight loss and recurrent fever deserves more attention than tiredness alone after a particularly demanding period. Similarly, repeated unexplained bruising together with abnormal bleeding should not be ignored.

The first step does not have to be a complicated investigation. Often, a careful history, physical examination and a basic blood count can help determine whether further testing is necessary.

The message is not to become anxious about every bruise or episode of tiredness. Blood cancers are relatively uncommon compared with the many benign causes of these symptoms. But neither should persistent symptoms be repeatedly dismissed.

Listen to what your body is telling you. When common symptoms persist without a clear explanation, a simple blood test can sometimes provide the first important clue - and, equally importantly, can help rule out serious disease.

(By Dr Prasad Narayanan, Lead Consultant - Medical Oncology Hematoncology and BMT, Manipal Hospital Yelahanka)

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