by Margaret
(Merced, ca)
QUESTION: A friend was suddenly told that he had diabetes and started medicine. His eyesight then became worse, and he was told that his kidneys were abnormal. After he stopped the medicine, he was told that his liver was abnormal even though it had seemed normal a month earlier. Could the diabetes diagnosis be wrong, or could the medicine have caused these problems?
These events do not prove that the diabetes diagnosis was wrong or that the doctors caused the kidney, liver, or eye problems. The diagnosis should be verified from the actual HbA1c and laboratory glucose results, while the exact medicine and kidney and liver numbers must be reviewed. High glucose itself can temporarily blur vision and can reveal previously silent kidney or liver disease. He should not stop or restart diabetes medicine without a prompt medical review and a safe replacement plan.
Answer by Dr. Albana Greca, MD, MMedSc
Hi Margaret,
The words “bad kidneys” or “bad liver” are not enough to judge the diagnosis. He needs copies of the reports, medicine name and dose, treatment dates, and the glucose results used for diagnosis. A second opinion is reasonable.
For a nonpregnant adult, diabetes can be diagnosed by one of these laboratory findings:
When there are no classic symptoms or emergency-level hyperglycemia, the abnormal result generally needs confirmation with a second abnormal test. A single home-meter reading is not enough. Review our guide to blood tests for diabetes.
Blurred vision can occur for days or weeks when very high glucose changes quickly after treatment begins. Fluid shifts in the eye can temporarily alter focus.
Worsening vision must not automatically be blamed on glucose. Newly diagnosed type 2 diabetes may already be accompanied by retinopathy, cataract, glaucoma, or another eye disorder. Persistent or unequal visual change needs a prompt dilated eye examination.
Kidney assessment requires serum creatinine with eGFR and urine albumin-to-creatinine ratio, or UACR. One abnormal result may need repeating because dehydration, infection, medicines, obstruction, or acute illness can temporarily change it.
Kidney disease may have existed before diabetes was discovered. Diabetes and high blood pressure are common causes, but a person with diabetes can also have kidney disease from another cause. The diagnosis should not be assumed without reviewing the pattern and duration of the abnormalities.
It depends entirely on the medicine. Metformin does not usually damage the kidneys, but kidney function determines whether it can be used safely because the drug is cleared through the kidneys. It is contraindicated when eGFR is below 30 mL/min/1.73 m² and may require reassessment or dose changes at higher levels of impairment.
Other diabetes medicines have different kidney-dose rules, side effects, and benefits. Bring every medicine package—including pain relievers, supplements, and nonprescription products—to the review. Do not assume that all organ abnormalities are caused by the newest prescription.
Liver tests may refer to ALT, AST, alkaline phosphatase, bilirubin, albumin, or imaging findings. An abnormal result can be caused by fatty liver disease, alcohol, viral hepatitis, gallstones, infection, muscle injury, supplements, or prescription medicines. Diabetes and excess weight are strongly associated with fatty liver disease.
A one-month change may reflect illness, medication, laboratory variation, or a fluctuating condition. The clinician should compare the exact values, symptoms, alcohol use, medicines, and previous reports.
Starting medicine at diagnosis can be appropriate. The decision depends on HbA1c, glucose severity, symptoms, weight loss, ketones, kidney and heart health, and the suspected type of diabetes. Lifestyle support is important, but it is not always safe to delay medicine while waiting for diet and exercise to work.
If glucose was very high or he had symptoms, treatment may have been urgently needed. If the diagnosis was based on a borderline result without confirmation, the records should be reviewed and testing repeated.
Use a blood sugar log and review our guide to diabetes medicine safety.
Seek urgent eye care for sudden vision loss, flashes, many new floaters, severe eye pain, or a curtain-like shadow. Seek urgent medical care for jaundice, dark urine, severe abdominal pain, repeated vomiting, marked swelling, very little urine, confusion, or severe weakness. Seek emergency care for difficult breathing, high ketones, glucose above 400 mg/dL, or a meter displaying “HI.”
Do not decide that the doctors are wrong—or that the medicine caused organ damage—without the actual records. Verify the diagnostic criteria, identify the exact prescription, and review kidney, liver, and eye findings separately. Stopping treatment without a replacement plan may allow dangerous hyperglycemia to return.
Educational safety note: This answer is for general diabetes education only. It does not replace personal medical advice, diagnosis, or treatment. Do not start, stop, restart, or change diabetes medicines, supplements, alcohol use, diet, or exercise without speaking with a healthcare professional.
Last reviewed: July 2026.
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