Rheumatoid Arthritis (RA): This is a common autoimmune disorder that causes inflammation in the joints, leading to pain, swelling, and stiffness. Elevated CRP (C-reactive protein) levels are often seen in active RA, making it a likely diagnosis given the symptoms and lab findings.

Osteoarthritis (OA): Although OA is more commonly associated with wear and tear of the joints, it can also cause significant body aches and joint pain. Inflammation in OA can lead to elevated CRP levels, though it's less common than in RA.
Lupus: Systemic lupus erythematosus is an autoimmune disease that can cause widespread inflammation, including joint pain and body aches. Elevated CRP levels can be seen during lupus flares.
Polymyalgia Rheumatica (PMR): This condition causes muscle pain and stiffness, particularly in the shoulders and hips, and is often associated with elevated inflammatory markers like CRP.

Septic Arthritis: This is a medical emergency where a joint becomes infected, leading to severe pain, swelling, and potentially life-threatening complications if not promptly treated. Elevated CRP levels can indicate the presence of an infection.
Endocarditis: Infection of the heart valves can cause systemic symptoms including joint pain and elevated CRP. It's a critical diagnosis to consider due to its high mortality rate if left untreated.
Lymphoma: Certain types of lymphoma can cause systemic inflammation, leading to body aches, joint pain, and elevated CRP levels.

Relapsing Polychondritis: A rare autoimmune disorder that causes inflammation in cartilage and connective tissue, leading to joint pain, body aches, and elevated inflammatory markers.
Sarcoidosis: A condition characterized by the growth of granulomas (inflammatory cells) in various parts of the body, which can cause joint pain, body aches, and elevated CRP levels.
Adult-Onset Still's Disease: A rare inflammatory disorder that causes high fevers, joint pain, and body aches, often with significantly elevated CRP levels.