Carotid arteries: When you have clogged arteries in your brain, it is a condition called carotid artery disease. Plaque will block or narrow the carotid arteries, and signs of a stroke may be present. Symptoms include breathing problems, sudden weakness, confusion, severe headaches, loss of consciousness, blurry vision, trouble with speech, paralysis, trouble walking, dizziness, unexplained falls, and loss of coordination or balance.
In addition, taking metformin in the long run can lead to kidney failure, digestive disease, diarrhea, etc.so, despite of no kidney problems, patients with diabetes should not rely on metformin in the long term. As a consequent, we can know that metformin has side effects on kidney, doing harm to kidney function.
Other possible side effects of metformin include headache, nausea, vomiting, change in taste and loss of appetite, muscle pain and flushing or increased sweating. It's also possible to have an allergic reaction to metformin. Symptoms of a severe allergic reaction include an itchy skin rash with hives, shortness of breath and difficulty breathing, along with swelling of the face, tongue and throat.