epiphenomenon

noun, plural ep·i·phe·nom·e·na [ep-uh-fuh–nom–uh-nuh] /ˌɛp ə fəˈnɒm ə nə/, ep·i·phe·nom·e·nons.

1. Pathology. a secondary or additional symptom or complication arising during the course of a disease.
2. any secondary phenomenon.

noun plural -na (-nə)

1. a secondary or additional phenomenon; by-product
2. pathol an unexpected or atypical symptom or occurrence during the course of a disease

n.

1. An additional condition or symptom in the course of a disease, not necessarily connected with the disease.