Fatigue and energy check
Tired all the time and told it is just life. Eleven markers, one collection, read together by a doctor.
The fatigue and energy check is an eleven-marker blood panel for women whose tiredness has never been properly investigated. It covers iron, red cells, thyroid, vitamin D, B12, folate, long-term blood sugar, kidney and liver function and inflammation in a single collection. It costs $179 with your own doctor's signed request, or $259 with a KnowLuna doctor who requests the panel and explains the results in a 20-minute video consult.
What it measures
- Iron studies: ferritin, serum iron, transferrin and saturation. Ferritin is your iron store, and it can be low enough to flatten your energy long before you are anaemic.
- Full blood count: haemoglobin, red cell size and white cells. It shows anaemia, and the red cell size hints at whether iron or B12 and folate are behind it.
- TSH: the first-line thyroid check. An underactive thyroid is one of the more common treatable causes found when tiredness is investigated.
- Free T4: the circulating thyroid hormone itself, read alongside TSH so a borderline result can be interpreted properly.
- Vitamin D: low levels are common in Australia over winter and in anyone who covers up or works indoors, and they are associated with tiredness and aching.
- Vitamin B12: needed for red cells and nerves. Low B12 is more likely if you eat little or no meat, or have had gut surgery.
- Folate: the partner marker to B12 for red cell production.
- HbA1c: average blood sugar over two to three months. Undiagnosed high blood sugar often presents as tiredness and thirst.
- Kidney function: creatinine, urea and electrolytes, plus an estimate of filtration rate.
- Liver function: the enzymes and proteins that show whether the liver is under strain.
- CRP: a general inflammation marker. A raised CRP does not say what is inflamed, but it tells your doctor to keep looking.
Who it's for
Women who are tired every day regardless of sleep, who feel foggy or forgetful, who are breathless on stairs they used to manage, who have heavy periods, who are vegetarian or vegan, who are in the year after a baby, or who have simply been told that tiredness is normal for their stage of life. It is for adults aged 18 and over.
What you'll learn, and what you won't
You'll learn whether one of the common medical causes of fatigue is present: low iron stores, anaemia, an underactive thyroid, low vitamin D, low B12 or folate, raised blood sugar, a kidney or liver signal, or ongoing inflammation. Each marker is explained against your laboratory's range and read as a pattern, so you get an answer rather than a list of numbers.
What it cannot do: it cannot measure sleep quality, mental load, low mood, sleep apnoea, pain, or the effect of caring for small children, and none of those shows up in blood. It also cannot confirm or exclude chronic fatigue syndrome, which is assessed clinically after other causes are checked. A blood test is one input to a doctor's assessment, not a diagnosis on its own.
Which cause each marker points to
| Possible cause | Markers that check it | What it can feel like |
|---|---|---|
| Low iron stores or iron deficiency anaemia | Ferritin, iron studies, full blood count | Flat energy, breathlessness on exertion, hair shedding, poor concentration, often with heavy periods |
| Underactive thyroid | TSH, free T4 | Cold intolerance, weight change, dry skin, constipation, slowed thinking |
| Vitamin D deficiency | 25-OH vitamin D | Aching muscles, low energy, worse over winter |
| B12 or folate deficiency | Vitamin B12, folate, full blood count | Tiredness, tingling in hands or feet, mouth soreness, poor memory |
| Raised blood sugar | HbA1c | Thirst, passing urine often, tiredness after meals |
| Kidney or liver strain | Kidney function, liver function | Often no symptoms at all, which is why it is screened |
| Ongoing inflammation or infection | CRP, full blood count | Tiredness with aches, low-grade fevers or a recent illness that has not settled |
This table is a guide to what each marker checks, not a diagnosis. Your doctor reads them together.
Reference ranges and what they mean
| Marker | Typical adult range | What it usually means |
|---|---|---|
| Ferritin | Laboratories print a lower limit of anywhere from 15 to 30 ug/L for women; under about 30 ug/L is widely treated in Australia as low iron stores, and many doctors want it comfortably above that when symptoms are present | A result under about 30 ug/L means depleted iron stores. Ferritin also rises with inflammation, which is why CRP is read beside it. |
| Haemoglobin | About 115 to 160 g/L, laboratory specific | Below range is anaemia. Red cell size points towards iron, or towards B12 and folate. |
| TSH | About 0.4 to 4.0 mIU/L | Above range suggests an underactive thyroid; below range suggests an overactive one. Free T4 refines the picture. |
| Vitamin D (25-OH) | 50 nmol/L or above at the end of winter is considered sufficient | Below 50 nmol/L is deficiency, graded as mild at 30 to 49 nmol/L, moderate at 12.5 to 29 and severe below 12.5. Levels drop over an Australian winter. |
| Vitamin B12 and folate | Laboratory-specific ranges; borderline B12 results are common and often repeated | A low or borderline result with symptoms is followed up rather than acted on once. |
| HbA1c | Below 6.0 percent (42 mmol/mol) is typical; 6.5 percent (48 mmol/mol) or above is in the diabetes range | Read with your history. A single raised result is confirmed on repeat. |
| Kidney and liver function | Laboratory-specific ranges | Mild changes are common and often mean very little; your doctor decides whether a repeat is worth it. |
| CRP | Usually reported as below about 5 mg/L in health | Raised CRP signals inflammation somewhere and prompts a closer look, not a conclusion. |
Ranges vary by laboratory; your report shows the range your lab uses. Typical ranges on this page are drawn from Pathology Tests Explained (RCPA) and the sources listed below.
When to do this test
No fasting is required, and a morning collection is best. Serum iron readings are steadier in the morning, and it fits an early appointment before eating becomes an issue. Avoid collecting while you have an active infection, or for a couple of weeks after one, because CRP and ferritin both rise with inflammation and can mask low iron. Any day of your cycle is fine, although testing just after a heavy period can show iron at its lowest. If you take iron, B12 or vitamin D, tell us, because recent doses can lift the reading. Tell us about any thyroid medicine your doctor has prescribed so the result is read the right way.
When to see a doctor promptly instead
Some tiredness needs to be seen, not booked in for pathology. See a doctor promptly, or go to an emergency department, if your tiredness comes with chest pain, breathlessness at rest, fainting, unexplained weight loss, drenching night sweats, a new lump, blood in the bowel or urine, coughing blood, a fever that will not settle, or thoughts of harming yourself. These are reasons for an in-person assessment first.
What a normal result means
All markers in range is a genuinely useful answer, not a dead end. It rules out the common measurable causes and moves the conversation to sleep, stress, mood, pain, perimenopause, medicines or a condition that is assessed clinically rather than in blood. Your doctor talks you through what to look at next and when a repeat is sensible, often three to six months later or sooner if symptoms change. Abnormal results are always followed up by a doctor.
How it works
- Order online. Either upload the request your own doctor has signed, or a KnowLuna women's health doctor reviews your short questionnaire and requests the panel.
- Collect at an accredited centre near you, in the morning, with no fasting needed. Or choose a home kit or a nurse visit (options below).
- Results are usually ready within a few business days, explained in plain English in your account, with a 20-minute doctor consult if you chose that option.
Choose how you collect
Every option is the same accredited test and the same report. Pick what suits you at checkout; the fee, if any, is added to either pathway price.
A quick draw at an accredited pathology collection centre near you. Usually under ten minutes. Included.
Lancet kit posted to you with an Express return satchel. If the lab cannot test your sample we send a replacement kit at no charge.
A near-painless device draws a small sample from the upper arm, with far fewer failed samples than a finger-prick. Express return satchel included.
A registered nurse comes to your home or workplace for a standard blood draw. Metro areas of capital cities; other locations on request.
Common questions
What blood tests should I get if I am always tired?
The usual first round is iron studies with ferritin, a full blood count, thyroid function, vitamin D, B12 and folate, HbA1c, kidney and liver function and CRP. This panel includes all eleven. Coeliac screening is sometimes added when there are gut symptoms, and your doctor can advise whether that applies to you.
Can a blood test find the cause of brain fog?
Sometimes. Low iron, an underactive thyroid, low B12 and raised blood sugar can all make thinking feel slow, and all four are in this panel. Brain fog also comes from broken sleep, stress, perimenopause and low mood, none of which show in blood. A clear panel narrows the search rather than ending it.
Do I need to fast for a fatigue blood test?
No. None of the eleven markers needs an overnight fast, including HbA1c, which reflects average blood sugar over two to three months. A morning appointment is still preferred for a steadier serum iron reading. If your doctor has added a fasting glucose or lipid test, follow the fasting instructions on that request.
Why am I so tired when my bloodwork is fine?
Because blood covers only part of the picture. Sleep apnoea, insomnia, chronic pain, low mood, medicines, perimenopause and simple overload all cause real fatigue with normal pathology. A normal panel is worth having, because it removes several possibilities and tells your doctor where to look next.
What are the red flags with fatigue?
Unexplained weight loss, night sweats, fevers that will not settle, a new lump, bleeding from the bowel or urine, coughing blood, chest pain, breathlessness at rest or fainting. Any of these means seeing a doctor promptly rather than waiting for a test result. Fatigue that starts suddenly and severely also deserves an in-person assessment.
How much does a fatigue blood test cost?
This panel is $179 when you bring your own doctor's signed request, or $259 when a KnowLuna doctor reviews your questionnaire, requests the panel and explains the results in a 20-minute video consult. It is self-pay, so it is not Medicare-rebated. Your own GP may be able to arrange some of these markers under Medicare.
Sources and further reading
- Pathology Tests Explained (RCPA): ferritin
- Pathology Tests Explained (RCPA): thyroid function tests
- Pathology Tests Explained (RCPA): vitamin B12 and folate
- Pathology Tests Explained (RCPA): HbA1c
- Pathology Tests Explained (RCPA): C-reactive protein (CRP)
- Healthdirect: fatigue
- Medical Journal of Australia: Vitamin D and health in adults in Australia and New Zealand, position statement (2012)
General information only, not medical advice. A test result is one input to a doctor's assessment, not a diagnosis on its own, and every abnormal result is followed up by a KnowLuna doctor. If your symptoms are severe or sudden, see a doctor promptly. Read our medical disclaimer.
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