Insulin resistance usually causes no symptoms, and health professionals do not routinely test for it (NIDDK). Standard blood tests look for prediabetes and diabetes, which can take years to develop. Instead, insulin resistance is usually suspected from conditions that tend to accompany it, such as abdominal obesity, high triglycerides, or polycystic ovary syndrome. Direct measures of insulin resistance are used mainly in research.
Symptoms such as increased thirst, frequent urination, blurred vision, unexplained weight loss, tingling or numbness in the hands or feet, and frequent infections are sometimes described as signs of insulin resistance. In fact, they are symptoms of high blood sugar, which usually means insulin resistance has already progressed to prediabetes or diabetes (NIDDK Symptoms & Causes of Diabetes). Fatigue is also often mentioned, but it has so many possible causes that it says little about insulin resistance on its own.
Some visible changes to the skin can be a clue, however. Acanthosis nigricans (dark, velvety patches of skin, often on the back of the neck or in the armpits) and multiple skin tags are more common in people with insulin resistance (NIDDK). They can prompt a health professional to look further, but neither one confirms insulin resistance.
Signs and symptoms are not the same thing
A symptom is something a person feels and reports, such as tiredness or hunger. A sign is something that can be seen or measured, such as a darkened patch of skin. The difference matters here because insulin resistance usually causes no symptoms (NIDDK), and the physical signs linked to it are associated with the condition but can’t confirm it.
Thirst, frequent urination, and similar complaints are often presented as insulin resistance symptoms, but they come from high blood sugar and appear on lists of diabetes symptoms (NIDDK Symptoms & Causes of Diabetes). Calling them “late” symptoms of insulin resistance implies an early-to-late progression that research hasn’t shown.
This means a symptom checklist can’t settle whether someone has insulin resistance. Having items on the list doesn’t confirm it, and having none doesn’t rule it out.
Why insulin resistance itself is usually silent
Insulin resistance means cells in muscle, fat, and liver respond less readily to insulin. The pancreas can compensate by producing more insulin, and while that compensation is enough to keep blood glucose in the normal range, a person may notice nothing at all (NIDDK).
That is the core reason symptom lists perform poorly here: the body can be doing extra work without generating any sensation that reports it. The insulin resistance overview covers what insulin resistance is and how it develops.
Physical signs that may appear
The two physical signs most often studied in connection with insulin resistance are acanthosis nigricans and multiple skin tags. Neither can diagnose it.
In studies that measured how well acanthosis nigricans performs, people with the sign were more likely to have insulin resistance, but a substantial share of people with insulin resistance didn’t have it. So the sign’s presence says more than its absence. How much it says depends on who was studied: their age, how common insulin resistance was in the group, and how the researchers defined insulin resistance.
Acanthosis nigricans
Acanthosis nigricans is darkened, thickened, or velvety-feeling skin, most often on the back or sides of the neck and in body folds such as the armpits or groin.
In 139 overweight adolescents aged 12 to 18 attending a pediatric obesity clinic, with insulin resistance defined as HOMA-IR at or above that study’s 90th percentile, acanthosis nigricans had a sensitivity of 63.3% and a specificity of 60.0% (Videira-Silva et al. 2019). In practical terms, in that clinic group roughly a third of the adolescents who met the study’s insulin resistance definition did not have the skin finding, and a substantial share of those who did not meet the definition had it anyway. Adolescents with acanthosis nigricans had a higher prevalence of insulin resistance in that clinic sample, but these are not general-population figures.
A separate study of 320 adults aged 40 to 60 reported specificity and positive predictive value but not sensitivity. Among normoglycemic participants, specificity was 0.85 and positive predictive value 0.86; among hyperglycemic participants, specificity was 0.90 and positive predictive value 0.96 (Álvarez-Villalobos et al. 2020). Read plainly: in those two adult groups, most participants who had the sign also met the study’s insulin resistance definition. Those figures cannot tell us how many adults with insulin resistance had no visible skin change, because that study did not report it.
Absence is the weaker signal, and one pediatric study shows why. Among 139 overweight African American and white children, 35% of those with fasting insulin above 20 µU/mL had no acanthosis nigricans, and, at a different threshold, 50% of those with fasting insulin above 15 µU/mL had no acanthosis nigricans (Nguyen et al. 2001). These are two separate thresholds, not a range. In the same study, differences associated with acanthosis nigricans were no longer statistically significant after adjustment for body fat mass and age.
Base rates matter as well. In a historical study of 1,412 sixth- and eighth-grade schoolchildren in Galveston, Texas, acanthosis nigricans was found in 2 of 440 white non-Hispanic children (about 0.5%), 19 of 343 Hispanic children (about 5.5%), and 80 of 601 Black children (about 13.3%) (Stuart et al. 1989). Those figures describe one historical cohort and should not be read as current prevalence, as evidence that ancestry causes the finding, or as diagnostic accuracy data. They illustrate that the prevalence of acanthosis nigricans varied substantially across groups in this historical cohort.
Acanthosis nigricans also has causes other than insulin resistance. Certain medications can produce it (Mourad & Haber 2021), and rare malignant or paraneoplastic forms exist (Leung et al. 2022). These are additional reasons the finding is not a stand-alone diagnosis.
Skin tags (acrochordons)
Skin tags are common, benign skin growths that become more frequent with age. Published prevalence estimates vary substantially, and the research on insulin resistance did not evaluate a single tag.
A cross-sectional study of 201 adult patients at a Brazilian university hospital compared people with multiple skin tags on the neck or in the armpits with people without them. Those with skin tags were more likely to have insulin resistance, as estimated by a blood-test-based index called HOMA-IR, and also had higher triglycerides and body mass index. The link with insulin resistance held after the researchers accounted for age, diabetes, waist-to-hip ratio, and other risk factors (Tamega et al. 2010).
A hospital-based cross-sectional study from North India with 70 cases and 70 controls found insulin resistance, by that study’s HOMA-IR criterion, in 41.4% of cases versus 17.1% of controls (Singh et al. 2020). Both numbers belong together: cases had a higher rate, and most cases still did not meet the study’s insulin resistance criterion. The authors noted the small sample as a limitation.
Another case-control study of 110 patients with two or more acrochordons and 110 controls examined impaired carbohydrate metabolism, diabetes, lipids, liver enzymes, and blood pressure rather than a direct insulin resistance reference standard (Şenel et al. 2023). Studies with diabetes outcomes are not interchangeable with insulin resistance studies. More recent exploratory work in a 371-person South Asian tertiary-care cross-sectional study examined cutaneous signs together with central obesity against metabolic syndrome and related traits (Saxena et al. 2025); it shows these signs continue to be studied alongside adiposity, not that they identify insulin resistance independently.
PCOS
Polyendocrine metabolic ovarian syndrome (PMOS), formerly called polycystic ovary syndrome (PCOS), is a condition in which insulin resistance is a recognized metabolic feature (Teede et al. 2026; Teede et al. 2023). Its metabolic features can occur in people who do not carry excess weight. International guidance notes that routine measures of insulin resistance are inaccurate and that clinical measurement of insulin resistance is not currently recommended (Teede et al. 2023).
Reported symptoms
Fatigue, food cravings, weight change, brain fog, post-meal energy crashes, shakiness, hair loss, and acne are frequently listed as insulin resistance symptoms. These experiences are real and may coexist with insulin resistance or with conditions in which insulin resistance is common.
But insulin resistance and prediabetes are usually silent (NIDDK), while fatigue appears on general diabetes symptom lists (NIDDK Symptoms & Causes of Diabetes) and has a very wide range of possible explanations. A sensation that is common in the general population and absent in many people with the condition cannot separate one group from the other.
What has held up, what hasn’t, and what remains disputed
Held up. Insulin resistance usually causes no symptoms (NIDDK). Acanthosis nigricans is associated with insulin resistance and hyperinsulinemia across multiple populations, but how strongly depends on the population: in the study of adults aged 40 to 60, specificity was high in both the normoglycemic group (0.85) and the hyperglycemic group (0.90) (Álvarez-Villalobos et al. 2020), while in overweight adolescents aged 12 to 18 both sensitivity (63.3%) and specificity (60.0%) were modest against that study’s HOMA-IR definition (Videira-Silva et al. 2019). Multiple skin tags show cross-sectional associations with insulin resistance measures but are not diagnostic (Tamega et al. 2010; Singh et al. 2020).
Hasn’t held up, or hasn’t yet. No validated early-to-late sequence of insulin resistance symptoms exists. Fatigue and cravings should not be presented as reliable predictors of measured insulin resistance. Staging language belongs, if anywhere, to the separate question of how hyperglycemia and diabetes develop (NIDDK Symptoms & Causes of Diabetes), not to insulin resistance symptoms.
Disputed. How much information acanthosis nigricans and skin tags add, independent of body fat and related traits, remains genuinely open. In overweight African American and white children, acanthosis nigricans-associated differences were no longer significant after adjustment for body fat mass and age (Nguyen et al. 2001). The Brazilian case-control study linked multiple tags to HOMA-IR, BMI, and triglycerides (Tamega et al. 2010), and recent exploratory work examines skin signs alongside central obesity and metabolic syndrome (Saxena et al. 2025). The evidence does not support a universal “independent marker” claim.
Frequently asked questions
Can you have insulin resistance with normal blood sugar?
Yes. When the pancreas produces enough additional insulin to compensate for reduced insulin responsiveness, blood glucose can stay in the normal range (NIDDK). A normal glucose result therefore does not by itself establish normal insulin sensitivity. The insulin resistance overview explains the mechanism further.
What are the early signs of insulin resistance?
No reliable early-to-late sequence of insulin resistance signs has been established, and insulin resistance can be present with no signs at all (NIDDK). Pages that stage symptoms as “early” and “late” are describing a timeline the evidence does not support. Acanthosis nigricans and multiple skin tags are associated findings in some studied populations (Videira-Silva et al. 2019; Tamega et al. 2010), but they are not diagnostic, and their absence does not rule out insulin resistance.
What does insulin resistance feel like?
Insulin resistance has no characteristic feeling that reliably identifies it. Fatigue, cravings, brain fog, and post-meal energy dips can occur for many reasons, and they are not established as reliable diagnostic symptoms of insulin resistance. That does not mean these experiences are imaginary or unimportant; it means they cannot tell you your insulin sensitivity.
Are the signs of insulin resistance different in women?
No separate validated female symptom checklist exists. Insulin resistance is a recognized metabolic feature of polyendocrine metabolic ovarian syndrome (PMOS), formerly called polycystic ovary syndrome (PCOS) (Teede et al. 2026; Teede et al. 2023). Menstrual irregularity and hyperandrogenic features such as excess hair growth belong to that syndrome, not to insulin resistance as a universal presentation in women.
Can children have signs of insulin resistance?
Yes, but the signs perform imperfectly. In a study of 139 overweight adolescents aged 12 to 18 from a pediatric obesity clinic, acanthosis nigricans had a sensitivity of 63.3% and a specificity of 60.0% against that study’s HOMA-IR definition of insulin resistance (Videira-Silva et al. 2019). In that group, many adolescents who met the definition did not have the skin finding, and many who had it did not meet the definition.
Conclusion
Insulin resistance is usually silent. Acanthosis nigricans and multiple skin tags may be associated with it in studied populations, but neither is a diagnosis: in selected adult groups the presence of acanthosis nigricans added meaningful information (Álvarez-Villalobos et al. 2020), while in overweight children and adolescents its absence did not rule out hyperinsulinemia or reduced insulin sensitivity (Nguyen et al. 2001; Videira-Silva et al. 2019). Commonly listed felt symptoms such as fatigue and cravings are not reliable ways to identify it. The insulin resistance testing guide covers what blood testing can and cannot establish.
References
- National Institute of Diabetes and Digestive and Kidney Diseases. Insulin Resistance & Prediabetes. National Institutes of Health. Last reviewed March 2025. Accessed September 16, 2026.
- National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of Diabetes. National Institutes of Health. Last reviewed October 2024. Accessed September 16, 2026.
- Videira-Silva A, Albuquerque C, Fonseca H. Acanthosis nigricans as a clinical marker of insulin resistance among overweight adolescents. Annals of Pediatric Endocrinology & Metabolism. 2019;24(2):99-103. doi:10.6065/apem.2019.24.2.99
- Álvarez-Villalobos NA, Rodríguez-Gutiérrez R, González-Saldivar G, et al. Acanthosis nigricans in middle-age adults: A highly prevalent and specific clinical sign of insulin resistance. International Journal of Clinical Practice. 2020;74(3). doi:10.1111/ijcp.13453
- Nguyen TT, Keil MF, Russell DL, et al. Relation of acanthosis nigricans to hyperinsulinemia and insulin sensitivity in overweight African American and white children. Journal of Pediatrics. 2001;138(4):474-480. doi:10.1067/mpd.2001.112657
- Stuart CA, Pate CJ, Peters EJ. Prevalence of acanthosis nigricans in an unselected population. American Journal of Medicine. 1989;87(3):269-272. doi:10.1016/S0002-9343(89)80149-4
- Mourad AI, Haber RM. Drug-induced acanthosis nigricans: A systematic review and new classification. Dermatologic Therapy. 2021;34(2). doi:10.1111/dth.14794
- Leung AKC, Lam JM, Barankin B, Leong KF, Hon KL. Acanthosis Nigricans: An Updated Review. Current Pediatric Reviews. 2022;19(1):68-82. doi:10.2174/1573396318666220429085231
- Tamega AA, Aranha AMP, Guiotoku MM, et al. Association between skin tags and insulin resistance. Anais Brasileiros de Dermatologia. 2010;85(1):25-31. doi:10.1590/S0365-05962010000100003
- Singh SK, Agrawal NK, Vishwakarma AK. Association of Acanthosis Nigricans and Acrochordon with Insulin Resistance: A Cross-Sectional Hospital-Based Study from North India. Indian Journal of Dermatology. 2020;65(2):112-117. doi:10.4103/ijd.IJD_646_18
- Şenel E, Salmanoğlu M, Solmazgül E, İnal BB. Acrochordons as a cutaneous sign of impaired carbohydrate metabolism, hyperlipidemia, liver enzyme abnormalities and hypertension: A case-control study. Journal of the European Academy of Dermatology and Venereology. 2023;37(9):1811-1814. doi:10.1111/jdv.4396
- Saxena A, Tiwari P, Gora A, et al. Cutaneous signs of insulin resistance with central obesity: insights into adipocentric metabolic dysfunction in South Asians. Frontiers in Clinical Diabetes and Healthcare. 2025;6:1691675. doi:10.3389/fcdhc.2025.1691675
- Teede HJ, Bahri Khomami M, Morman R, et al. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. The Lancet. 2026;407(10545):2329-2339. doi:10.1016/S0140-6736(26)00717-8
- Teede HJ, Tay CT, Laven J, et al. Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. Journal of Clinical Endocrinology & Metabolism. 2023;108(10):2447-2469. doi:10.1210/clinem/dgad463