Hi welcome to HCm I have gone thru your query regarding tingling and numbness with weird feeling in body . I can understand your concern . Numbness can have all kinds of different causes, as it is a symptom of many different ailments, diseases and conditions. That all is the outcome of your weak Immune System due to our faulty food habits and derailed life style . Dear , as far as I can understand your knee replacemt has no conecction with your present feelings , rather it is something psychological .Your worry about some other serious health condition , may have lead you such a situation . Hyperventilation , dehyderation ,Anxiety ,Iron Deficiency , Poor blood Circulation or Lack of blood ,High Blood Pressure (Hypertension) ar some of the causes . By removing the cause you can reinstate your health . That all is the outcome of your weak Immune System due to our faulty food habits and derailed life style . A proper diagnosis is required, so that you can treat the cause of the numbness rather than just treat the symptoms of numbness itself which include tingling and numbness . By removing the cause you can reinstate your health . I would like to suggest you to modify your life style and food habits . natural form - fresh fruit ,veges ,ginger, garilc ,amla ,Aloe vera juice , a spoon of turmeric powder + Almond oil with a cup of hot milk at bed time help stay healthy . And for eliminating gas /acidity ,do exercise , brisk walking ,yoga , Pranayam -deep breething , Vajjarassan , Kapalbhatti help alley acidity help stay healthy. Avoid fried fast foods too much of sugar, tea, coffee ,alcohol , smoking ,stress ,constipation . Hope this helps solves your query .Take care , All the best . Don t hesitate to get back if have any further query