At Shire Family Medical in Sutherland, persistent fatigue is one of the most common concerns GPs hear — and one of the most frequently dismissed by patients themselves. Tiredness is easy to explain away with a busy week or a run of poor sleep. But when low energy becomes the new normal, it is worth taking seriously.
This article explains what fatigue is, why it happens, what your GP may want to investigate, and when persistent tiredness warrants a closer look.
Why Am I So Tired? Understanding Fatigue
Fatigue is persistent exhaustion or low energy that does not resolve with rest or a good night’s sleep. Unlike ordinary tiredness, which improves after sleep or recovery time, fatigue tends to linger — sometimes for weeks or months — and can affect your ability to function at work, at home and in everyday life.
Fatigue is a symptom, not a diagnosis in itself. That distinction matters: it means there is usually a reason behind it, and that reason is worth finding.
What Does Fatigue Actually Feel Like?
Fatigue is not simply feeling sleepy. Many people describe it as a physical heaviness, a flatness they cannot shake, or a mental fog that makes concentration difficult.
Common signs of fatigue include:
- Waking up tired even after a full night’s sleep.
- Finding ordinary tasks harder than usual.
- Poor concentration, mental slowness or forgetfulness.
- Physical weakness or a sense of heaviness in the limbs.
- Low mood, irritability or reduced motivation.
- Needing to rest more than feels normal.
- Avoiding activities you used to manage easily.
Fatigue can come on gradually. Many people only recognise how tired they have become when they start scaling back things they used to do without a second thought.
Common Causes of Persistent Fatigue
Fatigue rarely has a single cause. More often, it reflects a combination of factors — physical, emotional and lifestyle-related — working together.
Sleep and Sleep Disorders
Poor sleep quality, insomnia, sleep apnoea, shift work and caring responsibilities can all disrupt the rest your body needs. Sleep apnoea in particular is frequently undiagnosed and can cause persistent daytime fatigue even in people who believe they are sleeping well.
Stress, Anxiety and Mental Health
Chronic stress, anxiety, depression, grief and burnout are among the most common drivers of fatigue. The mind and body are not separate systems — ongoing psychological load can affect sleep, appetite, immune function and energy levels in measurable ways.
Iron Deficiency and Anaemia
Low iron is one of the most common and reversible causes of fatigue, particularly for people with heavy periods, pregnancy, breastfeeding, low dietary iron intake or gastrointestinal symptoms. It is worth checking specifically because tiredness from iron deficiency may occur even before frank anaemia develops.
Thyroid Conditions
An underactive thyroid (hypothyroidism) can cause fatigue, weight changes, cold sensitivity and low mood. Thyroid problems are often missed because symptoms develop gradually and can be non-specific. A simple blood test can screen for this.
Blood Sugar and Diabetes Risk
Undiagnosed type 2 diabetes or elevated blood glucose can cause persistent tiredness alongside increased thirst, frequent urination and blurred vision. A fasting blood glucose or HbA1c test may be relevant depending on your history and risk factors.
Infections and Post-Viral Fatigue
Fatigue can linger for weeks or months after a viral illness, including flu, COVID-19 and glandular fever. This is common and does not necessarily indicate an ongoing infection, but persistent symptoms after illness should still be reviewed.
Medications
Some medications — including antihistamines, antidepressants, blood pressure medicines and sedatives — list tiredness as a side effect. If fatigue began or worsened around the time a medication was started or changed, it is worth raising with your GP.
Hormonal Changes
Perimenopause, menopause, pregnancy, postpartum recovery and hormonal fluctuations across the menstrual cycle can all affect energy, sleep and mood. Fatigue in these contexts often overlaps with other symptoms and is worth discussing as part of a broader health picture.
Other Medical Conditions
Heart disease, kidney or liver conditions, inflammatory or autoimmune conditions, and cancer can all present with fatigue. These are less common explanations but are among the reasons persistent or unexplained tiredness warrants proper medical review rather than ongoing self-management.
When Should You See a GP for Fatigue?
It is reasonable to book a GP appointment if fatigue has lasted more than two weeks, is not improving with rest, is getting in the way of normal life, or is simply worrying you.
Seek medical advice sooner if fatigue comes with any of the following:
- Unexplained weight loss.
- Shortness of breath or chest pain.
- Palpitations or fainting.
- Persistent fever or night sweats.
- Blood in stool, urine or vomit.
- Heavy or irregular periods.
- Low mood or thoughts of self-harm.
- Sudden or severe worsening of tiredness.
If any of these are present, do not wait. Call your GP or, if symptoms are severe or urgent, call 000.
What Your GP May Ask
A fatigue appointment usually starts with a careful history. The more specific you can be, the more useful the consultation will be. Rather than saying “I feel tired all the time,” try to describe what has changed — for example, “I used to walk 30 minutes without stopping, but now I need to rest after 10.”
Your GP may ask about:
- How long the tiredness has been present and whether it is improving or worsening.
- Sleep quality, duration, snoring or waking unrefreshed.
- Mood, stress, anxiety or reduced motivation.
- Diet, alcohol, caffeine and exercise habits.
- Periods, pregnancy, menopausal symptoms or relevant hormonal history.
- Recent infections or overseas travel.
- Current medications and supplements.
- Family history and previous blood test results.
Tracking symptoms for a week or two before your appointment — noting when fatigue is worst, how sleep is going and any other changes — can make the conversation significantly more productive.
What Blood Tests Might Be Ordered for Fatigue?
Blood tests are not always the first step, but they are commonly considered when fatigue is persistent, unexplained or associated with other symptoms. Your GP may discuss tests such as:
- Full blood count — to check for anaemia and other blood abnormalities.
- Iron studies and ferritin — to assess iron stores, not just haemoglobin levels.
- Thyroid function — to check for an underactive or overactive thyroid.
- Blood glucose or HbA1c — to screen for diabetes.
- Kidney and liver function — to identify conditions that can present with fatigue.
- Inflammation markers (CRP or ESR) — to detect inflammatory or autoimmune processes.
- Vitamin B12, folate or vitamin D — where clinically relevant.
Shire Family Medical, a GP medical centre at 154 Flora Street, Sutherland, offers on-site pathology collection on referral from your GP, making it straightforward to organise testing and review results together in a follow-up consultation.
Blood tests need to be interpreted in context — a result within the normal reference range does not always explain every symptom, and a normal result does not mean your concerns are unfounded. Our article on how blood test results work and what happens next explains how your GP uses results alongside your history and clinical picture, not in isolation.
Fatigue and Low Iron
Low iron deserves its own mention because it is among the most common, most overlooked and most treatable causes of fatigue. People at higher risk include those with heavy periods, recent pregnancy or breastfeeding, limited red meat intake, coeliac disease, gastrointestinal conditions, or a history of significant blood loss.
Symptoms of iron deficiency can include tiredness, weakness, dizziness, shortness of breath on exertion, poor concentration, headaches, restless legs and feeling unusually cold. These symptoms overlap with many other conditions, so blood tests — including iron studies and ferritin — are needed before assuming iron is the cause.
Where iron deficiency is confirmed, your GP may discuss likely causes and treatment options. For some patients, oral iron supplements may be appropriate. For others, iron infusions may be considered where oral iron is not tolerated or sufficient. Our article on what to expect from an iron infusion covers how this treatment may fit into a broader care plan where clinically indicated.
What If My Blood Tests Come Back Normal?
Normal blood test results can be genuinely reassuring — they help rule out several important causes and allow your GP to focus the investigation elsewhere. But normal results do not mean your symptoms are imaginary, and they do not end the conversation.
When initial blood tests return within normal ranges, your GP may explore:
- Sleep quality and the possibility of sleep apnoea — which blood tests cannot detect.
- Stress, anxiety, depression or burnout, which can cause profound physical fatigue alongside emotional exhaustion.
- Post-viral recovery, particularly if fatigue followed a recent illness.
- Medication side effects.
- Lifestyle factors such as diet, alcohol, hydration and physical activity.
- Whether further review or a specialist opinion is appropriate.
Persistent fatigue with no clear explanation after initial investigation is worth following up, not dismissing. Return to your GP if symptoms continue or worsen.
Fatigue After a Viral Illness
Post-viral fatigue — including fatigue following COVID-19, influenza and glandular fever — is common and can persist for weeks or months after the acute illness has resolved. It often comes alongside other symptoms such as brain fog, poor sleep, reduced exercise tolerance and mood changes.
Most people recover with time, paced activity, good sleep and hydration. However, ongoing post-viral fatigue should still be reviewed if it is not improving, is severe, or is accompanied by concerning symptoms such as breathlessness, chest symptoms or significant weight loss. A GP can help determine what monitoring or follow-up is appropriate for your circumstances.
Is a Broader Health Check Worth Considering?
If fatigue is part of a more general concern about your health — or if you have not had a thorough check-up in some time — a structured assessment may be useful. GP health assessments at Shire Family Medical can include a review of medical history, blood pressure, relevant pathology, screening needs and lifestyle factors, giving your doctor a more complete picture from which to work.
A check-up is not about testing everything at once. It is about reviewing what is relevant for you at this stage of life and deciding what to monitor or act on.
Fatigue Is Worth Taking Seriously
Persistent tiredness is common, but it does not have to be managed indefinitely without answers. Whether the cause turns out to be straightforward or requires more investigation, a GP consultation is the right starting point — not to immediately order every available test, but to listen carefully, consider the full picture and determine what is worth looking into next.
For patients in Sutherland and across the Sutherland Shire, Shire Family Medical is available to help assess ongoing fatigue, organise appropriate testing and guide follow-up care based on your individual circumstances.
Book a GP appointment to discuss persistent fatigue →
Frequently Asked Questions
Why am I so tired all the time?
Persistent tiredness — or fatigue — can have many possible causes, including poor sleep, iron deficiency, thyroid conditions, stress, anxiety, depression, blood sugar issues, post-viral recovery, hormonal changes, or other medical conditions. Because fatigue is a symptom rather than a diagnosis, identifying the cause usually requires a GP consultation and may involve blood tests or a broader health review.
When should I see a GP for tiredness?
See your GP if tiredness has lasted more than two weeks, is not improving with rest, is affecting your ability to work or carry out normal daily activities, or is simply worrying you. Seek medical advice sooner if fatigue is accompanied by unexplained weight loss, shortness of breath, chest pain, persistent fever, heavy bleeding, fainting, or low mood with thoughts of self-harm.
What blood tests does a GP order for fatigue?
Your GP may consider a full blood count, iron studies and ferritin, thyroid function, blood glucose or HbA1c, kidney and liver function, inflammation markers such as CRP or ESR, and vitamin B12, folate or vitamin D where relevant. The specific tests ordered will depend on your symptoms, history and risk factors — not every patient requires the same panel.
Can low iron make you tired?
Yes. Iron deficiency is one of the most common causes of fatigue, particularly in people with heavy periods, recent pregnancy or breastfeeding, limited dietary iron, or gastrointestinal conditions. Tiredness from low iron can occur before frank anaemia develops. Blood tests — including iron studies and ferritin — are needed to confirm whether iron deficiency is present before starting treatment.
What if my blood tests are normal but I’m still tired?
Normal blood test results are reassuring and help rule out several important causes of fatigue, but they do not always explain every symptom. Your GP may explore sleep disorders such as sleep apnoea (which blood tests cannot detect), stress, anxiety or depression, post-viral recovery, medication side effects, or lifestyle factors such as diet, alcohol and physical activity. Persistent fatigue with normal initial results warrants follow-up, not dismissal.
Can stress and anxiety cause fatigue?
Yes. Chronic stress, anxiety, depression, burnout and grief are among the most common causes of persistent fatigue. They can disrupt sleep, affect appetite and immune function, and cause both physical and mental exhaustion. Mental health is a legitimate and important part of any fatigue assessment — a GP may ask about mood and stress as part of a thorough history, not as a way of dismissing physical symptoms.
Should I book a long appointment for fatigue?
A longer appointment is often helpful when fatigue has been ongoing for some time, you have several symptoms to discuss, or you would like a broader health review alongside the fatigue assessment. When booking, let reception know that fatigue is your main concern — this allows your GP to set aside adequate time for a thorough history.
This article provides general health information only. It is not a substitute for personalised medical advice and does not create a doctor-patient relationship. Any treatment, test, procedure or vaccination mentioned is for illustrative purposes only — suitability depends on individual circumstances and assessment by a qualified health professional. Medical information can change; always speak with your GP about your specific symptoms, health history and care options. In an emergency, call 000.
