Check the markers behind feeling sick all the time
Ferritin, TSH, vitamin D, and glucose, measured in a single blood draw
- CLIA-certified labs
- HIPAA compliant
- Personalized health protocol
What feeling sick all the time can mean
Feeling sick all the time usually comes from one of four groups of causes: everyday digestion, stress, or sleep problems; nutrient or hormone shortfalls; long-term conditions; or repeated infections. Feeling generally unwell has a long list of possible causes, so it is worth raising with a provider when it happens often.
"Sick" can mean three different things. Nausea counts as chronic after 4 weeks or more of symptoms. Malaise is a general sense of being unwell, somewhere between healthy and sick. Getting sick often is a third pattern, and many cases start with something ordinary.
The most common causes of feeling sick all the time
Common causes of feeling sick all the time are everyday ones that affect the gut, your energy, or both. Each brings its own mix of symptoms, whether you feel constantly nauseous or simply run down.
| Cause | How it can feel | Examples |
|---|---|---|
| Digestive conditions | Nausea and stomach upset | Acid reflux (GERD), stomach or bowel infections, and slow stomach emptying (gastroparesis) |
| Stress and anxiety | Nausea, stomach cramps, and loose stools | Work pressure, worry, and low mood |
| Poor sleep | Tiredness that eases with better sleep habits | Short sleep and sleep apnea |
| Diet and dehydration | Tiredness, dry mouth, thirst, and dark yellow urine | Irregular meals and too little fluid |
| Medication side effects | Nausea and general malaise | Prescription medicines and nonmedical drugs |
| Pregnancy | Nausea, often in the morning | Morning sickness during pregnancy |
When no everyday cause fits, the next question is a nutrient or hormone problem that only blood work can measure.
Nutrient and hormone problems behind feeling unwell
Nutrient and hormone shortfalls can leave you tired or unwell most days, with symptoms that rarely point to one cause.
- Low iron stores: iron eased fatigue in adults with low stores but normal hemoglobin.
- Low vitamin B12: a deficiency can leave you feeling tired or weak.
- Underactive thyroid: fatigue, weight gain, and trouble tolerating cold are common but not specific to the thyroid.
- Low vitamin D: correcting a deficiency eased fatigue in one small trial.
- Blood sugar swings: glucose highs and lows can leave you unwell.
If results are normal, consider chronic conditions and infections.
Chronic conditions and infections behind feeling sick
Long-term conditions such as autoimmune disease and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) can make you feel sick most of the time. Among people with a rheumatic disease, about 1 in 2 is severely fatigued. ME/CFS brings fatigue lasting 6 months or longer that rest does not relieve.
If you keep getting sick, sleep and stress are worth checking. After virus exposure, adults sleeping 6 hours a night or less caught more colds than those sleeping more than 7 hours. In virus-exposed volunteers, infection rates also rose with stress. Tracking symptoms helps match a cause to your pattern.
Get 100+ biomarkers tested in-lab or at home
One blood draw a year. A full picture of your health, explained in plain language.
Get 100+ biomarkers tested in-lab or at home
One blood draw a year. A full picture of your health, explained in plain language.
How to narrow down why you feel sick
Narrowing down why you feel sick starts with recording its duration, symptoms, and triggers.
- Note the duration: 4 weeks of nausea counts as chronic
- Log symptoms: what appears, and when
- Track timing: after meals, short nights, or stressful days
- List changes: new medicines, supplements, or possible pregnancy
- Ask which blood tests fit your history
Routine tiredness workups usually check a blood count and thyroid-stimulating hormone (TSH). In UK primary care, ferritin was requested in only 9.4% of tiredness workups, and 26% of those results were out of range. Some symptoms cannot wait for results.
When to see a doctor or get emergency care
Most sick feelings can wait for a routine visit, but some signs cannot.
See a doctor soon:
- Unexplained weight loss: 10 pounds or 5% of body weight over 6 to 12 months
- A lasting fever: beyond 48 to 72 hours
Get care right away:
- Chest pain: pain spreading to the jaw or left arm, or chest pain with nausea or sweating (call 911)
- Confusion or a stiff neck with fever: get emergency help immediately
- Fluids will not stay down: for 12 hours or more
Otherwise, blood markers give a clinician something concrete to work from.
Get to know your baseline with Superpower
When you feel sick all the time, a comprehensive blood test checks markers a routine workup can leave unchecked. A Superpower membership includes 100+ biomarkers in a single draw, among them ferritin, iron, hemoglobin, TSH, vitamin D, and glucose. As your home for health, Superpower measures these markers and supports improving them with a personalized protocol, plus AI and care team support.
Your results give you and your clinician a clear place to start. Start your Superpower membership and get your baseline in one draw.
References
- Cleveland Clinic. Malaise. Updated November 3, 2025. Accessed October 17, 2026. https://my.clevelandclinic.org/health/symptoms/malaise
- Lacy BE, Parkman HP, Camilleri M. Chronic nausea and vomiting: evaluation and treatment. *Am J Gastroenterol*. 2018;113(5):647-659. https://doi.org/10.1038/s41395-018-0039-2
- MedlinePlus. Nausea and vomiting – adults. Medical Encyclopedia. National Library of Medicine. Reviewed July 22, 2025. Accessed October 17, 2026. https://medlineplus.gov/ency/article/003117.htm
- Harvard Health Publishing. The gut-brain connection. Harvard Medical School. July 18, 2023. Accessed October 17, 2026. https://www.health.harvard.edu/diseases-and-conditions/the-gut-brain-connection
- Latimer KM, Gunther A, Kopec M. Fatigue in adults: evaluation and management. *Am Fam Physician*. 2023;108(1):58-69.
- Houston BL, Hurrie D, Graham J, et al. Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials. *BMJ Open*. 2018;8(4):e019240. https://doi.org/10.1136/bmjopen-2017-019240
- Office of Dietary Supplements. Vitamin B12: fact sheet for consumers. National Institutes of Health. Updated December 15, 2023. Accessed October 17, 2026. https://ods.od.nih.gov/factsheets/VitaminB12-Consumer/
- National Institute of Diabetes and Digestive and Kidney Diseases. Hypothyroidism (underactive thyroid). National Institutes of Health. Last reviewed March 2021. Accessed October 17, 2026. https://www.niddk.nih.gov/health-information/endocrine-diseases/hypothyroidism
- Nowak A, Boesch L, Andres E, et al. Effect of vitamin D3 on self-perceived fatigue: a double-blind randomized placebo-controlled trial. *Medicine (Baltimore)*. 2016;95(52):e5353. https://doi.org/10.1097/MD.0000000000005353
- Overman CL, Kool MB, Da Silva JA, Geenen R. The prevalence of severe fatigue in rheumatic diseases: an international study. *Clin Rheumatol*. 2016;35(2):409-415. https://doi.org/10.1007/s10067-015-3035-6
- MedlinePlus. Myalgic encephalomyelitis/chronic fatigue syndrome. National Library of Medicine. Updated May 1, 2024. Accessed October 17, 2026. https://medlineplus.gov/myalgicencephalomyelitischronicfatiguesyndrome.html
- Prather AA, Janicki-Deverts D, Hall MH, Cohen S. Behaviorally assessed sleep and susceptibility to the common cold. *Sleep*. 2015;38(9):1353-1359. https://doi.org/10.5665/sleep.4968
- Cohen S, Tyrrell DA, Smith AP. Psychological stress and susceptibility to the common cold. *N Engl J Med*. 1991;325(9):606-612. https://doi.org/10.1056/NEJM199108293250903
- Handjiev S, Nobes J, Murphy MJ. 'Tired all the time': what general practitioners request and find in patients with tiredness/fatigue - an audit against NICE clinical knowledge summary of tiredness/fatigue in adults. *Ann Clin Biochem*. 2025;62(5):416-419. https://doi.org/10.1177/00045632251329175
- MedlinePlus. Weight loss – unintentional. Medical Encyclopedia. National Library of Medicine. Reviewed January 1, 2025. Accessed October 17, 2026. https://medlineplus.gov/ency/article/003107.htm
- MedlinePlus. Fever. Medical Encyclopedia. National Library of Medicine. Reviewed July 31, 2024. Accessed October 17, 2026. https://medlineplus.gov/ency/article/003090.htm
- MedlinePlus. Chest pain. Medical Encyclopedia. National Library of Medicine. Reviewed April 28, 2026. Accessed October 17, 2026. https://medlineplus.gov/ency/article/003079.htm
- MedlinePlus. Meningitis. Medical Encyclopedia. National Library of Medicine. Reviewed November 10, 2024. Accessed October 17, 2026. https://medlineplus.gov/ency/article/000680.htm
Heart & Vascular Health
Metabolic Health
Energy
Liver Health
Kidney
Sex Hormones
Thyroid Health
Nutrients
Immune System
Inflammation