Disclosed are methods, apparatuses, etc. for glucose sensor signal purity analysis. In certain example embodiments, a series of samples of at least one sensor signal that is responsive to a blood glucose level of a patient may be obtained. Based at least partly on the series of samples, at least one metric may be determined to characterize one or more non-physiological anomalies of a representation of the blood glucose level of the patient by the at least one sensor signal. A reliability of the at least one sensor signal to represent the blood glucose level of the patient may be assessed based at least partly on the at least one metric. Other example embodiments are disclosed herein.