Hi welcome to HCm I can understand your concern for severe tightness and pain in the calf muscle. Though , uncomfortable but they’re a surprisingly common problem. In fact, they’re one of the most frequent complaints . Your symptoms may be due to problems with the hamstring or calf muscles themselves, such as excessive tightness or fatigue. Muscle fatigue or tightness is usually due to overuse, either from - 1. Excessive activity , old age or 2. dehyderationor 3. poor choice of footwear . As per your info that you are taking enough of water and you have not exercised recently so that you can be over worked .So First 2 of the causes are ruled out . Either injury or chronic disease can cause inflammation to any of the tissues of the leg and lead to leg pain. For women, wearing excessively high-heeled shoes increases tension and stress in the calves and hamstrings. Your symptoms could also be due to pressure and irritation of the nerves in your leg. Dear ,Our over all health depends on the immunity of our system . You can prevent tight calves by doing regular exercise , Yoga - pranayam- Inhale - hold -Exhale - hold for 10 times . to boost your blood circulatin stretching exercises ,massage & rubbing with warm Til oil , giving pressure of and on , applying hot pack on pain full patch , is soothing . A balanced diet including all essential nutrients -protien , vitamins , minerals , nuts , Antioxidants - ginger, garlic , lemon juice ,Turmeric powder in a cup of hot milk in breakfast and at bed time helps alley pains and inflammation It is a natural antibiotic and helps in early recovery by boosting your immunity . +modifying your life style further strengthen your immune system paving way fou total health . Get checked your BP & Sugar level under control Don t over exert . Avoid fried , fast foods , tea , cofee , alcohol , smoking , constipation ,dehyderation If you face problem on a frequent basis ,rush to your Doctor .Ultimately a diagnosis by a medical professional is necessary so that the appropriate treatment can be commenced as soon as possible. Hope this helps solves your query .Take care , All the best . Don t hesitate to get back if have any further query