Osteoarthritis (OA) is one of the most common forms of arthritis. It is a chronic condition in which the material that cushions the joints, called cartilage, breaks down. This causes the bones to rub against each other, causing stiffness, pain & loss of joint movement. 
Common risk factors for osteoarthritis include increasing age, obesity, previous joint injury over of the joint, weak thigh muscles & genetics. 
Description of osteoarthritis from modern aspect. 

Types – There are two types of OA – primary and secondary.
Primary osteoarthritis is generally associated with aging and the “wear and tear” of life. The older you are, the more likely you are to have some degree of primary Osteoarthritis. However, not everyone gets it- not even the very old. That’s because OA is a disease, and not part of the normal aging process. Secondary osteoarthritis, in contrast, tends to developed relatively early in life, typically 10 or more years after a specific cause, such as an injury or obesity. Osteoarthritis occurs most often in knees, hips and hands. Other joints, particularly the shoulders, can also be affected. OA rarely affects other joints, except as a result of injury or unusual physical stress. The pain and stiffness of osteoarthritis can make it difficult to do daily activities including your job, play sports or even get around with ease. That’s why it’s important to learn all you can about this disease & manage it at early stage. 

Signs & Symptoms:

Osteoarthritis symptoms usually develop gradually. At first, there may be soreness or stiffness that seems more like a nuisance than a medical concern.

1. Sore or stiff joints- particularly the hips, knees and lower Back after inactivity or overuse.
2. Stiffness after resting that goes away after movements.
3. Pain that is worse after activity or toward the end of the day. 
4. Osteoarthritis may also affect the neck, small finger joints, base Of thumb, ankle and big toe. The pain may be moderate and come and go, Without affecting the ability to perform daily tasks. Some people’s OA will never progress past this early stage. Others will have their OA get worse. The pain & stiffness of more severe Osteoarthritis may Make it difficult to walk, climb stairs, sleep or perform other daily tasks. 

Our body & the universe is made up of same basic constituents namely Prithvi, Aap, Vayu, Tej & Aakash. Out of those Asthi(Bone)tissue is made up of Agni (Digestive Fire), Prithvi, Aap mahabhutas. So we can easily understand that meda & Mans has from the diet that we take, seven dhatus are prepared in sequence like Ras, Rakta, Mansa, Meda, Asthi, Majja & Shukra utmost importance in the formation of Asthi dhatu. Bony cage holds the internal organs properly. Once the Asthi-dhatu is deranged, joint & bone pain starts. Teeth, hair, nails becomes weak & fragile. 

Pathology of OA-Sandhigat Vaat-From Aayurvedic perspective- 

Pathology of Sandhigat Vaat is stated in two ways- 
1. Santarpanjanya– In this type of OA vitiated Kafa,Meda are responsible. Suppressed metabolism, overeating, frequent ingestion of cold & refrigerated food stuffs, day time sleeping, lack of exercise tend to hamper proper & complete digestion-which further leads to formation of aam (a non digestable toxic substance) This aam is accumulated in joints. This creates inflammation & pain. 

2. Apatarpanjanya– Excessive physical activities, malnutrition, improper sleep, spicy & bilious diet, constipation-these are some factors that vitiate & increase Vaat dosh in the body. Excess Vaat dosh suppresses Asthi-dhatu which causes Asthi kshaya & this leads to degeneration of cartilage also.All these cause pain in joints.