In lymphoma, unexplained fever, drenching night sweats, and significant unintended weight loss are sometimes referred to as B symptoms. These symptoms can help doctors assess the disease, but they can also occur with infections and other medical conditions.

The National Cancer Institute identifies unexplained fever, night sweats, fatigue, weight loss, and swollen lymph nodes among the possible symptoms of non-Hodgkin lymphoma. Source: NCI – Non-Hodgkin lymphoma.

When should you be concerned?

A fever that lasts longer than expected, repeatedly returns, or is associated with unexplained night sweats and weight loss should be assessed by a doctor.

The duration and severity matter, as do the person's age, medical history, medications, and immune status.

People receiving chemotherapy, taking immune-suppressing medication, or living with a weakened immune system should follow their healthcare team's fever instructions. Fever during chemotherapy can represent a medical emergency.

Seek urgent medical care for fever accompanied by confusion, difficulty breathing, a stiff neck, severe dehydration, or other serious symptoms.

A fever does not mean that cancer is present. Infections remain a much more common cause. The purpose of evaluation is to identify the actual reason rather than allowing an unexplained problem to continue.

15. Changes in Lymph Nodes: Swelling That Persists Should Be Checked

The lymphatic system is an essential part of the body's immune and fluid-management systems.

It consists of lymph vessels, lymph nodes, and other tissues that help transport lymph fluid, support immune responses, and filter harmful substances.

Lymph nodes are small structures distributed throughout the body. They are commonly found in the neck, underarms, chest, abdomen, and groin.

When the body fights an infection, lymph nodes may become enlarged. This is a normal immune response and often happens during conditions such as a sore throat, dental infection, or respiratory illness.

For example, someone with a throat infection may notice tender lumps beneath the jaw or along the sides of the neck.

These swollen nodes usually become smaller as the infection improves.

However, persistent or unexplained lymph node enlargement deserves medical attention because certain cancers can affect the lymphatic system.

Lymphoma is a cancer that begins in lymphocytes, a type of white blood cell involved in immune defense. Leukemia and other cancers can also affect lymph nodes, while cancers that begin elsewhere in the body may spread to nearby lymph nodes.

Potential warning signs include:

• A new lump in the neck, underarm, or groin.

• Swelling that continues without an obvious infection.

• A lymph node that gradually becomes larger.

• Persistent swelling accompanied by unexplained fever.

• Drenching night sweats.

• Unintended weight loss.

• Ongoing fatigue.

• Unexplained itching or discomfort.

Not every enlarged lymph node is painful. Some people discover a firm lump without experiencing any other symptoms.

However, tenderness alone does not reliably determine whether a lymph node is benign or cancerous.

According to the National Cancer Institute, swollen lymph nodes, fever, drenching night sweats, fatigue, and unexplained weight loss are among the possible symptoms of non-Hodgkin lymphoma. Source: NCI.

What should you do if you notice a swollen lymph node?

Pay attention to its location, approximate size, tenderness, and how long it has been present.

If swelling does not improve after an infection resolves, continues to grow, feels unusually firm, or occurs without an obvious explanation, arrange a medical evaluation.

A doctor may examine the area and consider blood tests, ultrasound, imaging, or a biopsy if necessary.

Do not repeatedly press or massage a swollen lymph node in an attempt to make it disappear. Doing so may irritate the surrounding tissue without addressing the underlying cause.

Most swollen lymph nodes are associated with infections or inflammation. Nevertheless, persistent enlargement should be investigated rather than ignored.

Why These Symptoms Are Easy to Overlook

One of the biggest challenges in recognizing cancer is that its early symptoms can look remarkably similar to everyday health problems.

A person who feels tired may blame a demanding job. Someone with abdominal discomfort may assume they ate something unsuitable. A persistent cough may be attributed to seasonal allergies, while changes in urination may be dismissed as a normal consequence of aging.

These explanations are often correct. The problem arises when people become so accustomed to their symptoms that they stop noticing how unusual they have become.

There are several reasons why potential cancer symptoms may go unnoticed.

1. The symptoms develop gradually

Some cancers grow slowly, producing subtle changes that become noticeable only over time.

A person may initially experience mild fatigue, occasional digestive discomfort, or a small change in appetite. Because the symptoms do not interfere significantly with everyday activities, they may not seem important.

However, when symptoms gradually become more frequent or severe, it is worth reconsidering whether the original explanation still makes sense.

2. People become accustomed to discomfort

Living with a persistent cough, recurring heartburn, irregular bowel movements, or chronic fatigue can gradually become part of someone's routine.

Instead of investigating the problem, people may simply adapt.

They might take medication more frequently, avoid certain foods, sleep longer, or reduce their activities without addressing the underlying reason.

While managing symptoms can provide temporary relief, it does not necessarily identify their cause.

3. Fear of a serious diagnosis causes delays

Some people avoid medical appointments because they are afraid of discovering something serious.

They may hope that the symptom will disappear on its own or convince themselves that it is probably nothing.

Unfortunately, avoiding an examination does not eliminate the possibility of illness. It only delays finding out what is happening.

A medical evaluation can actually provide reassurance when symptoms are caused by a harmless condition. If a serious condition is discovered, an earlier diagnosis may provide more treatment options.

4. Not all cancers cause obvious symptoms

Another important misconception is that cancer must produce pain, a noticeable lump, or severe physical discomfort.

This is not true.

Some cancers develop with few noticeable symptoms, particularly during their early stages. Others produce general symptoms that are difficult to distinguish from ordinary illnesses.

This is why paying attention to changes in your body and following appropriate screening recommendations are both important.

5. People underestimate the importance of unusual changes

A symptom does not have to be severe to deserve attention.

For example, a small amount of blood in the urine, unusual vaginal bleeding, a new breast lump, or a mole that has changed appearance may not cause significant discomfort.

Nevertheless, these changes can provide important diagnostic clues.

Rather than waiting until a symptom becomes unbearable, seek advice when something is clearly different from what is normal for you.

When Should You See a Doctor?

There is no single waiting period that applies to every possible cancer symptom.

The appropriate timing depends on the symptom, its severity, the person's age, medical history, and other risk factors.

The National Cancer Institute advises people to seek medical attention when symptoms persist for a couple of weeks without improvement. However, certain symptoms require assessment much sooner.

A practical approach is to consider three important characteristics.

Duration: Has the symptom continued longer than expected? Does it keep returning?