Hello, Welcome to Just Answer and thanks for your question. eGFR stands for Glomerular Filtration Rate. It is a calculated number based on age, race, sex and creatinine level. It is used to track kidney function. A level of 55 is Stage 3 chronic kidney disease. Here is the chart for Chronic Kidney Disease:
Stages of chronic kidney disease
Normal kidney function
90 mL/min or more
Kidney damage with normal or high GFR
Kidney damage and mild decrease in GFR
60 to 89 mL/min
Moderate decrease in GFR
30 to 59 mL/min
Severe decrease in GFR
15 to 29 mL/min
Less than 15 mL/min or on dialysis
Your treating medical providers will have to determine why your kidneys aren't functioning properly. Some possible reasons are obesity and high blood pressure. Normal weight for your height is 125-168 pounds; overweight is 169-202 pounds and obesity is anything over 202 pounds. Getting these two things under control with a healthy diet and exercise along with blood pressure medication if you have hypertension should improve the numbers.
The creatinine is used to calculate eGFR so one can track the level of kidney failure. ALT is one of the liver enzymes. It is high but not seriously so. One possible cause is non-alcoholic steatohepatitis (NASH) which is fatty liver disease.
You should be seeing a doctor on a routine basis so you can find out why you have kidney trouble and if the high ALT is from fatty liver or some other disease. You also need to control hypertension if you have it and get on a diet and exercise program. It is a serious matter to have kidney function that low at your age.