Coping with chemotherapy side effects and cancer fatigue

A cancer diagnosis brings a lot to take in, and chemotherapy often comes with its own set of challenges. Many people find the side effects, and the deep tiredness that can follow, just as hard to cope with as the treatment itself.

The good news is that most side effects can be eased, and there is support available to help you feel more like yourself day to day.

In this guide, we look at the common side effects of chemotherapy, when they tend to start, and why cancer and its treatment can leave you feeling so exhausted. We also share some practical ways to manage symptoms, and where plant-to-patient medical cannabis may have a role to play in supporting comfort, alongside your usual cancer care.

What are the side effects of chemotherapy?

Chemotherapy works by targeting fast-growing cells in the body. Cancer cells grow quickly, but so do some healthy cells, such as those in your hair follicles, mouth, and digestive system. This is why chemotherapy can affect more than just the cancer itself.

Common side effects include:

• Nausea and vomiting

• Tiredness and low energy

• Hair loss

• A sore mouth or mouth ulcers

• Changes in appetite

• Diarrhoea or constipation

• A higher risk of infection, as chemotherapy can lower your white blood cell count.

Not everyone experiences the same side effects, and how severe they are can depend on the type of chemotherapy you are having, the dose, and your general health. Some people find their symptoms are mild, while others need extra support to get through treatment. Your oncology team will monitor you closely throughout and can adjust your care if side effects become difficult to manage.

What are the worst side effects of chemotherapy?

For many people, nausea and vomiting are the side effects they worry about most, though anti-sickness medicines have improved a great deal in recent years and can make a real difference. Extreme tiredness, often called fatigue, is also commonly described as one of the hardest parts of treatment, as it can affect every part of daily life.

A weakened immune system is another serious concern, as it leaves you more vulnerable to infections. If you develop a temperature, or feel unwell in any way during chemotherapy, it is important to contact your care team straight away, as this may need urgent attention.

Other side effects, such as hair loss or changes in taste, are not medically dangerous but can still be distressing and affect how you feel about yourself. Support is available for this too, so it is always worth mentioning to your team if something is affecting you emotionally as well as physically.

When do chemotherapy side effects start?

Side effects can begin within a few hours of treatment, though some appear a few days later. Nausea, for example, often starts on the day of treatment or the day after. Fatigue tends to build gradually and may become more noticeable as a course of chemotherapy continues. Hair loss usually begins two to three weeks after the first session.

Everyone responds differently, so your care team can give you a clearer idea of what to expect based on your specific treatment plan.

Does cancer make you fatigued?

Yes, fatigue is one of the most common and often most overlooked effects of cancer and its treatment. It is different from normal tiredness. Cancer-related fatigue can leave you feeling exhausted even after plenty of rest, and it does not always improve with sleep alone.

There are several reasons why cancer and chemotherapy can cause this level of exhaustion. The cancer itself can affect the body's energy levels, while chemotherapy can lower red blood cell counts, leading to anaemia, which makes you feel tired and short of breath. Treatment can also disrupt sleep, appetite, and mood, all of which add to the overall feeling of fatigue. Stress and anxiety about a diagnosis can play a part too, as coping with cancer is both a physical and emotional experience.

Fatigue can affect anyone having chemotherapy, regardless of age or fitness levels, and it often lingers for some time after treatment has finished.

What does cancer fatigue feel like?

People describe cancer fatigue in different ways, but many say it feels heavier and harder to shake off than everyday tiredness. Simple tasks, such as making a meal or having a conversation, can feel like a real effort. Some people describe a kind of mental fog, finding it harder to concentrate or remember things. Others notice their arms and legs feel weighed down, or that they need to rest several times throughout the day.

It is important to know that this is a recognised and common part of cancer treatment, not a sign that something is going wrong, and it is not something you simply have to push through alone.

How to manage and minimise chemotherapy side effects

Small, practical steps can help. Resting when you need to, pacing daily activities, and accepting help from family or friends can make a real difference to how you cope. Eating little and often, staying hydrated, and gentle movement, such as short walks, can also help with both energy levels and nausea. Your care team can prescribe anti-sickness medication and may suggest ways to manage other symptoms as they arise, so it is always worth speaking up about how you are feeling.

Managing nausea and supporting quality of life

Medical cannabis cannot treat cancer, and it is not a treatment for cancer symptoms themselves. However, in the UK, it is recognised as an option that some patients explore, under specialist supervision, specifically to help with chemotherapy-induced nausea and vomiting, particularly where standard anti-sickness medicines have not worked well enough.

Any complementary treatment should always be discussed with your oncology team first, to make sure it fits safely alongside your existing care plan.

Can medical cannabis help with cancer?

This is one of the most common questions we're asked, and it's an important one to be clear about. Medical cannabis is not a treatment for cancer itself. It cannot be prescribed to treat, shrink or cure a tumour, and any source suggesting otherwise should be treated with real caution.

What it may be considered for is some of the symptoms and side effects that can come with cancer and its treatment. In the UK, cannabis-based medicines are recognised as an option for chemotherapy-induced nausea and vomiting where standard anti-sickness medicines haven't worked well enough. Some patients are also assessed for wider symptoms such as persistent pain, appetite loss or difficulty sleeping, always as one part of a broader care plan rather than a replacement for it.

Whether it's suitable is a decision for a specialist clinician, made individually. Eligibility depends on your diagnosis, your symptoms and what you've already tried. It's also important to speak to your oncology team before adding anything new, as some treatments can interact with cancer therapies.

Speaking to someone…

If you're living with cancer, or supporting someone who is, please know that finding this overwhelming is completely normal. There's no expectation that you should have it all worked out, and no rush to make decisions about anything.

Your oncology team remains the best first port of call for questions about your treatment and symptoms, and organisations such as Macmillan Cancer Support offer free, confidential advice from specialist nurses if you'd like to talk something through with someone outside your immediate care.

At Medicann, our prescribing doctors take time to understand your full picture, including any side effects you're experiencing and how they're affecting your daily life, before making any recommendation. Consultations are unhurried, there's no obligation to proceed, and being assessed doesn't commit you to anything. If it isn't the right option for you, we'll tell you.

If you'd like to explore whether it might help, you can read more about how our process works, check your eligibility online, or get in touch to speak with one of our specialists. Whenever you're ready is the right time.