The Board has denied the veteran's claim for service connection for a back disability, finding that there is no clear and unmistakable evidence of preexisting condition and that the current back disability did not increase in severity during active duty.

The Veteran's hypertension, left knee patellofemoral syndrome, and right knee patellofemoral syndrome have been granted service connection as secondary to his service-connected disabilities. The lumbar spine disability has also been granted but the effective date is not specified.

The Board has remanded the Veteran's claims for service connection and increased rating for various conditions, including allergic rhinitis, sleep apnea, degenerative disc disease of the lumbar spine, lower extremity radiculopathies, and left lower extremity radiculopathy with foot drop. The issues include determining if these conditions are related to service or other factors.

The Veteran's service-connected disabilities have prevented him from securing and maintaining substantially gainful employment since June 30, 2018. The Board has granted a TDIU effective July 1, 2018.

The Veteran's right ear hearing loss is denied as there was no evidence of a current disability.,Left ear hearing loss is granted, with the condition being service-connected due to exposure during active duty and worsening over time.,Service connection for reflux esophagitis with hiatal hernia is granted based on symptoms that began in-service and continue post-service.,Service connection for stenosis of the cervical spine is granted as it was likely caused by service, including combat duties.,Degenerative disc disease of the lumbar spine is granted due to continuity of symptomatology since service.,Chronic fatigue syndrome is granted based on symptoms that began in-service and continue post-service.